Step 1

In a small bowl, combine minced garlic, rosemary, thyme, oregano, black pepper, salt, coriander, cumin, lemon zest, lemon juice, olive oil, and mustard

Step 2

Mix into a thick, fragrant paste

Step 3

Lay the lamb flat, fat side down

Step 4

Rub half the marinade inside the meat, then roll and tie it securely with butcher’s twine

Step 5

Rub the remaining marinade all over the outside of the lamb

Step 6

Place in a dish, cover, and refrigerate for 4–12 hours to marinate

Step 7

Remove the lamb from the fridge about 1 hour before cooking

Step 8

Let it rest at room temperature to ensure even cooking

Step 9

Preheat oven to 300°F (150°C)

Step 10

Scatter sliced onions, carrots, and celery in the bottom of a roasting pan

Step 11

Add water or broth to the pan

Step 12

Place a roasting rack over the vegetables and set the lamb on top

Step 13

Drizzle with a little olive oil

Step 14

Roast uncovered for about 3–3½ hours or until internal temperature reaches 145°F (63°C) for medium doneness

Step 15

Baste the lamb once or twice with pan juices during cooking

Step 16

For a more browned crust, increase the oven temperature to 425°F (220°C) for the last 15 minutes of roasting

Step 17

Transfer the lamb to a cutting board and tent loosely with foil

Step 18

Let it rest for 20–30 minutes before slicing

Step 19

Strain pan drippings and serve as a jus or reduction sauce if desired