Roast a lamb rack whole and add crisp smashed potatoes for fuss-free entertaining

Rack of lamb, slathered in mustard and rosemary and roasted over crushed potatoes, makes for a simple and smart main dish.
Rack of lamb, slathered in mustard and rosemary and roasted over crushed potatoes, makes for a simple and smart main dish. PHOTO: NEW YORK TIMES

(NYTIMES) - I am an ardent vegetable lover, but, sometimes, what I really want to eat is meat and potatoes. 

It could be a weeknight pan-grilled steak, just big enough for two, cooked on the rare side of medium-rare and served with baked potatoes. Or perhaps juicy braised short ribs and a creamy potato puree. I could go on. 

If guests are coming, a simple meat-and-potatoes option makes for carefree entertaining, especially during the winter holidays. Add a vegetable or two on the side and a green salad. Done. 

For lamb lovers, a good option is Irish stew, simmered with potatoes on top, a humble but eminently satisfying feast. Francophiles can roast a fine garlic-studded leg or shoulder of lamb to send to the table with a potato gratin. 

It is the tender rack of lamb, however, that makes the most perfect roast for an elegant dinner and it is the easiest to prepare. It may be the priciest cut, but a home-cooked rack of lamb is still far cheaper than one from a restaurant. 

Usually, lamb racks are sold “frenched” (trimmed of fat, with the bones separated and scraped clean) and ready to cook. A good butcher will take care of this for you. Supermarket racks often need a bit more trimming.

Frenching them at home is not necessary, but do remove extraneous fat. Each eight-bone rack, once cooked, may be sliced into four thick chops (my preference) or eight thin chops, if you prefer.

A simple seasoning with salt and pepper is fine, but a little more effort will yield a much more flavourful result. I mix pounded garlic and anchovy with Dijon mustard and olive oil into a quick paste to smear on the meat, and add a shower of roughly chopped rosemary. Give this marinade at least 10 minutes to do its work, or longer if possible, up to eight hours. 

To combine the meat and potatoes for roasting, I choose my new favourite way with potatoes – crushed. Small potatoes are first boiled in their skins, then squashed flat, drizzled with olive oil and baked until crisp: in this case, right under the lamb, where they can absorb some of the flavours from the 
meat. 

I learnt this method from Argentine chef Francis Mallmann. In Argentina and Uruguay, these potatoes are called papas aplastadas, which simply means flattened or crushed, but sounds fancy. You will find recipes for them in most South American cookbooks, often with directions to crisp on an iron plancha, or griddle, rather than roast. 

If you are well organised, you can prepare this meal several hours in advance and pop it in the oven at the appropriate moment. Guests are always impressed with the presentation, a festive turn on meat and potatoes.

Rosemary Rack of Lamb With Crushed Potatoes

INGREDIENTS
2 lamb racks, about 680g each, preferably frenched
Salt and pepper
2 Tbs Dijon mustard
3 cloves garlic, minced
4 anchovy fillets, minced
5 Tbs extra-virgin olive oil
680g to 900g small, round potatoes, scrubbed and left whole
2 Tbs roughly chopped rosemary
2 Tbs roughly chopped parsley, for garnish

METHOD
1. Bring a large pot of salted water to a boil. Season lamb generously with salt and pepper. In a small bowl, mix together Dijon mustard, garlic and anchovy (or pound together in a mortar for a smoother texture). Stir in 3 Tbs olive oil. Smear lamb all over with marinade and set aside. 
2. Meanwhile, boil potatoes until the tip of a paring knife meets no resistance, 10 to 15 minutes depending on size. When potatoes are done, drain, transfer to a roasting pan large enough to hold them in a single layer, and set aside to cool. 
3. Heat oven to 200 deg C. With palms or the back of a wooden spoon, crush potatoes gently to crack open and slightly flatten. Sprinkle with salt, drizzle with about 2 Tbs olive oil and turn to lightly coat. 
4. Lay lamb racks on top of potatoes, with bones curving downwards. Scatter rosemary over meat and potatoes. Roast, uncovered, until a 
meat thermometer registers 50 deg C (for medium-rare), about 20 minutes. (Cook to about 60 deg C for medium.)
5. Remove lamb to a cutting board and let rest, tented with foil. Return potatoes to oven and leave to roast 10 to 15 minutes more, until nicely crisped. 
6. Use a large chef’s knife to slice the racks by cutting between the bones. One rack will yield four thick chops or eight thin ones. Transfer chops and potatoes to a warm platter, sprinkle with parsley and serve. 

Serves four