NEW YORK (NYTIMES) - Smoke is shorthand for culinary catastrophe, setting off alarms in the kitchen and jitters in nervous cooks. But some foods will reward you for pushing them right over the edge, past done and headed toward burned.

"My burning method of choice is the broiler," said chef Gerardo Gonzalez, who draws inspiration from traditional Mexican moles to make his own at Lalo, the restaurant he opened last fall in Chinatown in Manhattan.

Gonzalez starts his mole with almonds, cashews, peanuts and pumpkin seeds, which are all toasted zealously, to the darkest possible shade of brown. "Just before they go black," he said.

From the blackened avocados at Nix to the lamb heart ashes at Aska, burned and charred foods may seem like just another fad sweeping through pyrotechnically inclined restaurants. But burning, a technique that can involve a surprising amount of shading and subtlety, has deep roots in many cuisines.

A great kazandibi, the Turkish milk pudding, requires a totally scorched bottom to fulfill its delicious potential, the milk pushed to the same shade as a fire-licked marshmallow. Any dessert that relies on a touch of burned sugar, from flan to crème brûlée, will go limp and lifeless if that caramel is cooked too lightly. And there are few primal delights like the burned ends of a barbecued brisket, crisp-edged and fierce with smoke.

Gonzalez, 34, who was raised in San Diego by parents from Jalisco, Mexico, first toyed with burning when he cooked at El Rey Coffee Bar & Luncheonette, a cafe on the Lower East Side in Manhattan that developed a cult following while he was in the kitchen.

He says Mexican cuisine has taught him how incorporating a burned vegetable or fruit, like onion or citrus, into vegetarian dishes will produce a serious, almost meatlike depth of flavour.

His mole, cooked down with charred tomatillos, onions and oranges, is based on the flavours of his youth, plumped up with the body and sweetness of dried apricots and plums. He deploys it in small amounts to intensify a bowl of hominy in broth.

"A friend told me it reminded them of a stew their Jamaican grandma used to make, but there are people who still don't get it," Gonzalez lamented. He has tweaked the dish a few times since Lalo opened, hoping to find an audience for the mole's intense flavours.

Gonzalez himself is mindful of the potential health risks in some browned foods; he generally avoids deeply charring meats because of studies that show it produces chemicals that can increase the risk of cancer.

Britain's Food Standards Agency warned this week against browning starchy foods like bread and potatoes because cooking them at high temperatures produces acrylamide, which has been linked to cancer in animals. Researchers are still studying whether the chemical affects health in humans. The Food and Drug Administration has said it is not clear if the low levels of acrylamide found in food may be a health risk, especially if eaten in small amounts.

Many people have a taste for thoroughly browned foods, crusty corners and inky, bittersweet edges - in moderation. When I was growing up, my mother, who is Indian, embossed her soft chapatis with tiny, crisp bubbles of black char, the pattern like a signature. The most coveted one in the stack was always the darkest, shining with clarified butter.

To understand the appeal of these strategically charred foods, I spoke with Andrea Nguyen, 47, a cookbook author and cooking teacher who lives in Santa Cruz, California. She said it was a matter of both taste and looks.

"Charred food always draws you in more, whets your appetite," she said.
It's why nuoc mau, a burned caramel sauce, is used to elegantly expand both flavour and colour in traditional Vietnamese cooking. Sugar is cooked with a little water until it is past golden, smoking and rushing toward a glowing dark russet.
The caramel is added in small amounts to marinades, or pots of simmering meat, which it infuses with umami, bringing a savoury sweetness along with a touch of bitterness. It is not just a one-dimensional burned flavour, but what Nguyen called "a liquid replication of the charred effect."
"It's not for ice cream," she added.

Nuoc mau was developed by resourceful Vietnamese cooks with simple stoves, she said. Using clay pots, they did not always have the luxury of browning foods as they cooked. The sauce served as a kind of replacement for the Maillard reaction, the chemical dance between amino acids and sugars that produces distinct savoury notes in browned foods.

"It allowed them to create big flavours using limited resources," Nguyen said.

Cooks throughout the Caribbean also use a sauce of burned sugar, known as browning, to amplify savoury flavours.

Though chef Rawlston Williams does not draw attention to it on the menu at his Brooklyn restaurant, the Food Sermon, he uses browning to marinate and braise lamb shanks, mimicking the colouring and elemental flavour of meats roasted over a fire.

"The longer it heats, the deeper and more pronounced the caramel becomes in the dish," he said. "I don't like it to become too profound. I like it to be a little more subtle."

Williams, 40, learned to use browning as a child in St. Vincent and the Grenadines. While neighbours employed the technique in meat dishes, as well as in the molasses-colored fruitcake known as black cake, in Williams' vegetarian household, it was often used to perk up the taste of seitan, a meat substitute he made from scratch.

Caramelising the sugar thoroughly, burning it yet not completely blackening it, is the key to an effective browning sauce, no matter how it is being used. It is through caramelisation that the vapid sweetness of sugar becomes interesting.

As sugar turns from pale gold to brown, the chemical reactions result in new flavours: acidity, tang and alcoholic notes, along with a more nuanced sweetness. They also introduce a little bitterness, which can add dimension.

"Everyone is so afraid of burning things," Canadian author Jennifer McLagan said. "But when you're burning, you're creating all of these different compounds that make food more complex in taste, and much more interesting to eat."

For her 2014 cookbook, Bitter: A Taste Of The World's Most Dangerous Flavor, McLagan, 63, developed a recipe for toast soup, based on a French country dish that stretches leftover bread into a meal. What sounds like a sad Dickensian sort of ration is in fact a strong case for burning good sourdough.

McLagan's version starts with a base of bacon-infused chicken stock. She adds bread, so diligently carbonised that your average toast prude might be tempted to carry it to the sink and scrape it clean with a knife. (Resist, please.)

Once ripped into pieces, soggy with stock, the toast is blitzed until smooth with a little hot milk and mustard, totally reconfiguring the burned flavour, diluting it into something more gently smoky, mellow and comforting.
McLagan warned against undertoasting the bread, which results in a tasteless soup.

"Of course, you don't want it totally acrid," she said, "but you do want to burn it a little." The toast should be blackened on its edges and deep brown all over.

Exercised with care, the dark arts of burning can conjure a world of flavour. But cooks have to push things a little further than usual, to fight their instincts and ignore the flutter of panic that sets in when food goes beyond a textbook golden brown into darker terrain, and curls of smoke send a warning that something has gone terribly wrong.

"When I'm pulling something from the salamander, someone is always walking by saying, 'Uh-oh, somebody burned something!'" Gonzalez said. "I'm like, 'Yes, that's the whole point.'"