3 recipes to enjoy the magic of citrus

Yotam Ottolenghi’s rosemary, olive oil and orange cake. For chef Ottolenghi, lemon is what makes food sing, whether it is a final squeeze of lemon juice to balance a dish or a few strips of pared lemon to infuse a stew. Baking is no exception. PHOTO: NYTIMES
Yotam Ottolenghi’s mojito-inspired lime, mint and rum tarts. PHOTO: NYTIMES

LONDON (NYTimes) - When I was a child, we often spent our summers in Italy. My grandparents were Italian, and we would stay with them in their house, in the hills outside Florence. It was complete madness for my dad's family to still have the house - it was grand, crumbling and soaking up all available funds - but magic for us kids, of course, less aware of all the headaches.

A big part of this magic came from the vast and largely empty structure in the garden called the limonaia. In parts of Italy, limonaias - lemon houses - are where citrus trees in their terra-cotta pots are taken during the winter months to shield them from the unforgiving frost and heavy rain. On big citrus estates, limonaias would often be tall and elaborate buildings, built around imposing columns and cathedral-like as a result.

Once the frost had passed and the citrus trees were no longer in need of protection, they'd be returned to their groves, leaving the limonaia to sit empty through the summer. The appeal of that empty space - slightly creepy with its vacant pots and random vines growing wild on the inside wall - was enormous for my brother and me. We'd spend hours clambering around and hiding out, the smell of citrus still hanging vividly in the air.

Lemons, then, have become a bit mythical for me. They are with me every step of the way, and not just as a memory and a tradition, but as a source of so much of what makes me happy in the kitchen. They leave their bright mark all over my savoury cooking: a final squeeze of lemon juice to balance a dish, some finely chopped preserved lemon skin to bring bursts of flavour and surprise, a few strips of pared lemon to infuse a stew. Lemon, for me, is what makes food sing.

Citrus in all its forms appears as often in my baking as it does in my savoury cooking, even when it's not shouting about itself. As with the limonaia during those summer months in Italy, citrus doesn't always need to be seen for its presence to be felt. Sometimes, of course, the citrus is loud and clear: Limes and oranges are very much the lead act in today's bakes, for example. Often, though, the role played by citrus is more of a supporting one and - if we define magic as that which brings about an effect without showing its hand at work - a little bit magic.

This magic can still be about scent and flavour: the grated lemon zest in a butter-rich pastry shell, or the subtle hint of orange zest in a batch of cranberry, oat and white chocolate cookies. It can be about the way citrus balances other flavours in a dish: the addition of lemon zest and juice in an almond paste, for example, to prevent it from being too sickly sweet, or the juice and zest of limes used to cut through the richness of a cheesecake. It can also, though, be about the huge utility of citrus in baking: its functional role as an acid and the effect it can therefore have on other ingredients.

Take the act of whisking egg whites to make simple meringues (or cakes or soufflés). For the egg whites to increase sufficiently in volume when they are being whipped, they need to be stabilised by the addition of something acidic. While cream of tartar is often used, a few drops of lemon juice per egg white works just as well. Or think of when lemon juice is added to apples or blueberries that are being cooked to make jelly or jam. To set, the gelling agent in fruit, pectin, needs to be coaxed out. A teaspoon or two of lemon juice is enough to make that happen.

Oranges and lemons are the workhorses of my kitchen, but I've barely scratched the citrus surface here; no mention of grapefruit or sour oranges, mandarins or the mottled skin and powerful scent of bergamot, bitter Seville oranges or Sicilian blood oranges, all kind of limes and yuzu or kumquats.

Just one bit of practical advice: Whether you're juicing or zesting or cutting out the segments of flesh to chop up, be sure to avoid the white pith in the membrane, which encases each segment. Crushing this will release a bitterness into the dish, rather than bringing the brightness and balance that citrus so beautifully provides.


Rosemary, Olive Oil and Orange Cake

Yield: 10 servings Total time: 1½ hours, plus time for preparing crystallised rosemary

PHOTO: NYTIMES

Ingredients
For the crystallised rosemary:
10 small rosemary sprigs, no more than 3cm each in size (see note)
1 egg white, lightly whisked
2 tsp granulated or superfine sugar (caster sugar)

For the cake:
About 2 Tbs/30g unsalted butter, softened, for greasing the pan
2 cups/240g all-purpose flour (plain flour), more to flour the pan
¾ cup/160ml extra-virgin olive oil
½ cup plus 1 tsp/120g superfine sugar (caster sugar)
1 Tbs finely grated orange zest (from about 1½ oranges)
1½ Tbs/7g packed finely chopped rosemary leaves
2 large eggs
½ cup/130g sour cream
2 tsp baking powder
¼ tsp salt

For the orange icing:
1½ Tbs freshly squeezed orange juice
2½ tsp freshly squeezed lemon juice
1¾ cups/175g sifted confectioners' sugar, or 1½ cups/150g sifted icing sugar

Method
1. At least 6 hours before you plan to ice the cake, prepare the crystallised rosemary: Brush rosemary on all sides with a little of the egg white and then dip it in the sugar, so the needles are lightly coated on all sides. Set aside on a wire rack to dry. Repeat with remaining rosemary. NOTE: For the rosemary, you want small, decorative clusters of needles. The simplest way to do this is to pull the smaller, bottommost clumps off of large sprigs, or trim off the very tops of several sprigs.

2. Make the cake: Heat oven to 160 deg.C. Generously grease a 23-cm Bundt pan with half the butter and refrigerate for 10 minutes. Butter again, generously, and then flour it, tapping away the excess.

3. Put olive oil, superfine sugar, orange zest and chopped rosemary leaves in the bowl of an electric mixer fitted with the whisk attachment. Whisk on medium speed until combined, then add eggs, one at a time. Whisk for another minute, until thick, then add sour cream and mix until combined on low speed. Scrape down the sides of the bowl and the whisk.

4. Sift flour, baking powder and salt together into a small bowl. Add the dry ingredients to the olive oil mixture and mix until combined. Increase speed to high and whisk for 1 minute.

5. Scrape batter into the Bundt pan and smooth the top with a small spatula. Bake for 30 to 35 minutes, or until cake is cooked and a skewer inserted into the middle comes out clean. Remove from oven and let cool for 10 minutes before inverting onto a serving plate. (You may want to trim the cake at this stage, if it rises unevenly, to allow it to sit flat on the plate.)

6. Prepare the icing: In a small bowl, whisk together orange juice, lemon juice and confectioners' sugar until smooth. When the cake has cooled, drizzle icing on top, allowing it to drip down the sides of the cake, then top with the crystallised rosemary and serve.


Lime, Mint and Rum Tarts

Yield: 12 tarts Total time: About 1 hour, plus chilling

PHOTO: NYTIMES

Ingredients
For the pastry:
1 cup/150g all-purpose flour (plain flour), more for rolling out dough
6 Tbs/80 grams cold unsalted butter, diced 1 Tbs plus 1 tsp/20g granulated or superfine sugar (caster sugar)
1/4 tsp salt
1/4 tsp white wine vinegar
2 Tbs ice water

For the curd:
½ cup/120ml lime juice (from about 5 to 6 limes), plus the zest of 2 limes, cut in wide strips, avoiding bitter white pith
⅔ cup/120g granulated or superfine sugar (caster sugar)
1 packed cup/25g mint leaves, plus 12 small mint leaves (or regular leaves, shredded just before using) for garnish
2 Tbs dark rum, plus 1 Tbs for serving
6 parsley leaves
2 large eggs plus 5 large egg yolks
2 tsp cornstarch (corn flour)
7 Tbs/100g cold unsalted butter, diced
1 Tbs Demerara sugar

Method
1. Make the pastry: Place flour, butter, sugar and salt in the bowl of a food processor. Pulse a few times, until mixture is the consistency of fine bread crumbs, then, with the machine on, slowly add vinegar and ice water. Process for a few seconds, until pastry starts to come together, then dump the dough onto a clean surface. (It will be very sandy.) Gather and pat the dough into a disc that is roughly 3cm-thick. Wrap in plastic wrap and refrigerate for 1 hour, or overnight.

2. While the pastry chills, make the curd. First, make the lime syrup: Bring lime juice and granulated sugar to a boil in a medium saucepan over high heat. Cook for 1 to 2 minutes, swirling frequently, until sugar has melted, and then boil for another minute. Remove from heat, add lime zest, along with a generous cup/10g mint leaves, and set aside for 10 minutes to infuse.

3. While the syrup cools, make the herb paste: Pour 2 Tbs rum into a spice grinder with the parsley and remaining scant ⅔ cup/15g of the mint. Pulse for about 10 seconds, until a paste forms, scraping down the sides of the work bowl and pulsing and/or shaking the machine again, if necessary. Set aside. (Alternately, you can whirl the herbs in a small food processor until chopped and then reduce the mixture to a paste in a mortar and pestle. Or, finely chop the herbs on a cutting board and, adding a small amount of rum at a time, work the mixture into a paste with the edge of a large knife.)

4. Strain lime syrup into a large heatproof bowl; squeeze the leaves and zest to extract as much flavor as possible and then discard. In a separate large bowl, whisk together 2 whole eggs, 5 yolks and the cornstarch until no lumps remain, and then stir into the cooled lime syrup.

5. Add scant 2cm of water to a medium saucepan, bring to a simmer over high heat and reduce the heat to medium. Place the bowl of eggs and syrup over the pan of gently simmering water and whisk continuously for 6 to 8 minutes, or until you have a thick, mousselike curd. Add butter and stir for an additional minute, or just until butter has melted, then remove from heat and set the curd aside to cool for about 10 minutes. Stir reserved herb paste into the curd, cover the surface directly with plastic wrap and refrigerate for at least 1 hour, until completely cool.

6. On a lightly floured work surface, tap the chilled pastry all over with a rolling pin to soften slightly before rolling out until 1 to 2mm-thick, using additional flour sparingly to prevent the dough from sticking. (The dough should be about 30cm in diameter.) Using a 9- or 10-cm round cookie cutter, cut out 8 circles and gently ease these into the cups of a muffin tin. Press down to fill the cups and press the sides so that the pastry rises to the rim of the cup; doing this will help you fill the tarts generously. Re-roll the remaining pastry to form 4 more circles and transfer to the muffin tin. Chill for at least 1 hour or overnight.

7. Heat oven to 180 deg. C. Blind-bake the pastry: Line the pastry shells with either paper muffin liners or squares of parchment paper. Fill with pie weights, rice or dried beans and then bake for 18 minutes, or until the pastry shells are a light golden brown around the edges and inside. Remove the parchment paper liners and weights and return the pastry to the oven for another 6 to 7 minutes, until dark golden brown. Quickly and carefully remove the shells from the muffin tin and set aside to cool completely on a wire rack.

8. To serve the tarts: Spoon 2 to 3 Tbs (about 40g) of the curd into each tart shell, or enough curd to fill the shell up to the rim. Smooth the surface of the curd with the back of a knife. Sprinkle the centre of each tart with a pinch of Demerara sugar and then arrange the small mint leaves or shredded mint on top. Finally, drizzle each tart with few drops of the remaining tablespoon of rum.


Rice Fritters With Orange Blossom Custard

Yield: 16 fritters Total time: 45 minutes, plus chilling

PHOTO: NYTIMES

Ingredients
For the fritters:
½ cup/100g arborio rice
2 cups/500ml whole milk
3 Tbs/40g granulated or superfine sugar (caster sugar)
1 star anise
Finely grated zest of 1 lemon
Finely grated zest of 1 orange
Salt
1 vanilla bean (vanilla pod), slit open lengthwise, seeds scraped out and reserved
About 3½ cups/800ml vegetable oil, for frying, more as needed
2 Tbs rum
2 large eggs, whites and yolks separated
½ cup/50g currants
½ cup plus 1 Tbs/70g all-purpose flour (plain flour)

For the custard (optional):
¾ cup/170ml whole milk
⅔ cup/150ml heavy cream (double cream)
3 Tbs/40g granulated or superfine sugar (caster sugar)
Zest of 1 orange, shaved in thin strips 1 vanilla bean (vanilla pod), slit open lengthwise, seeds scraped out and reserved
2 large egg yolks
2 Tbs/20g cornstarch (corn flour)
½ tsp orange blossom water
1 tsp lemon juice

For finishing:
3 Tbs/40g granulated or superfine sugar (caster sugar)
1 Tbs plus 1 tsp ground cinnamon

Method
1. Prepare the rice for the fritters: In a medium saucepan over medium heat, stir to combine the rice, milk, sugar, star anise, lemon and orange zest, a pinch of salt and the vanilla bean and scraped seeds. Once milk begins to simmer, reduce heat to low and cook rice for 25 to 30 minutes, until the liquid is almost all absorbed, stirring occasionally to make sure it doesn't stick to the bottom of the pot. Transfer cooked rice to a medium container, let cool for about 15 minutes, then cover and refrigerate for about 2 hours, or overnight. (If you chill the mixture overnight, let it come to room temperature before forming the fritters.)

2. Make the custard: Heat the milk, heavy cream, sugar, orange zest and vanilla bean and seeds in a small saucepan over medium-high heat. Remove from heat when bubbles begin to form around the edges, about 2 minutes.

3. In a separate small bowl, whisk egg yolks with the cornstarch, orange blossom water and lemon juice to make a smooth paste. Slowly pour the warm milk and cream into the paste, whisking continuously to make sure there are no lumps.

4. Return the mixture to the pan over medium heat and cook for about 3 minutes, until you get a thick custard, whisking constantly. Remove the orange zest and vanilla bean, scraping off any custard that clings. Transfer to a small bowl, let cool for about 15 minutes, then cover the surface directly with plastic wrap and refrigerate for at least 1 hour or overnight, until completely cool and set.

5. Just before serving, fry the fritters: Fill a deep saucepan with about 5cm vegetable oil and bring to 180 deg C. over medium heat. (You may need more than 3½ cups/800ml oil; getting the proper depth is important to make sure the fritters fry properly.)

6. Meanwhile, mix cinnamon and sugar together and set aside on a large plate. Remove the rice mixture from the fridge and discard the star anise and vanilla bean. Using your hands, break up the rice mixture, then stir in the rum and the two egg yolks until the mixture is uniform, using your hands if necessary. Add currants and flour and mix well to combine.

7. Whisk the two egg whites with a pinch of salt in a stand mixer on high speed until stiff peaks form. Gently fold egg whites into rice mixture until no streaks of white remain.

8. Once the oil is up to temperature, use two tablespoons to drop spoonfuls of the rice mixture into the oil; each fritter should be a 3cm-sphere. (An old-fashioned ice cream scoop also works well.) Fry five or six fritters at a time, for 1 to 2 minutes on each side, until crisp, golden brown and puffy. Using a slotted spoon, transfer fritters to a paper towel-lined plate to remove excess oil, and then immediately roll in the cinnamon sugar. Serve warm by themselves, or with the cold custard if you've made it, or with some whipped cream.

Yotam Ottolenghi is a British chef and the author of several cookbooks, including "Plenty," "Plenty More" and, with Sami Tamimi, "Jerusalem." He is also an owner of the Ottolenghi cafes and Nopi restaurant in London.

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