Note: I used half of a boneless leg of lamb for a family dinner, but feel free to roast a full leg - with to without the bone - just adjust the cooking time accordingly. For a full boneless leg of lamb, calculate about 25 minutes per pound; for a bone-in roast you'll need to cook it for about 15 minutes per pound of its total weight. Learn more About Lamb Cuts here.
Prep Time: 20 minutes
Cook Time: 1 hour, 15 minutes
Total Time: 1 hour, 35 minutes
Yield: Makes 6 to 8 servings
- 3 lbs. boneless leg of lamb, tied into a roast (see note above for options)
- 1 tsp. fine sea salt
- 1 tsp. freshly ground back pepper
- 3 cloves garlic
- 2 Tbsp. olive oil
- 1 tsp. rosemary or thyme leaves (optional)
- 4 parsnips and/or carrots
- 2 lbs. mixed root vegetables - potatoes, turnips, onions, rutabagas, celery root, and kohlrabi are good choices
- Pat the lamb dry. In a small bowl, combine the salt and pepper. Peel and mince the garlic and add it to the bowl along with 1 tbsp. of the olive oil. Combine this into a paste. Mince the herbs, if you're using them, and work them into the paste too. Rub the garlic paste all over the lamb, working it into any creases or areas of the lamb that separate from one another. Roll the lamb into a roast and tie it with kitchen string, if necessary to help it keep its shape (I find often it sort of holds together fine without being tied). Let the lamb marinate in the paste for at least an hour and up to overnight, covered and chilled.
- Preheat an oven to 375°F. While the oven heats, bring the lamb to room temperature. Trim and peel the parsnips and/or carrots. Cut them into quarters lengthwise, cutting out the tough core in the parsnips.Use about 1 tsp. of the olive oil to lightly coat the bottom of a roasting pan. Arrange the carrots and/or parsnips in a row in the center of the pan and place the lamb on top of them. Trim and peel the other root vegetables and cut them into chunks. Arrange them around the lamb, drizzle them with the remaining 1 tsp. of olive oil, and sprinkle them lightly with salt. Put the pan in the oven.
- After about 40 minutes, remove the pan and sort of toss the vegetables in the pan juices a bit. Return to the oven. Cook until the lamb measures 145°F with a meat thermometer for medium-rare or up to 160°F for medium (I really don't recommend cooking lamb past medium, but well-done lamb would measure 170°F), about 1 hour 15 minutes total cooking time for a 3-pound roast (calculate about 25 minutes per pound of a boneless, tied roast for medium-rare).
- Let the roast sit, covered, for at least 15 minutes and up to 30 minutes before carving or cutting it. This resting time allows the roast to finish cooking, and for the juices to redistribute throughout the meat for a more tender, juicier roast.
- Serve, cut into slices, with root vegetables alongside.