Never-Fail Boneless Leg of Lamb

Preheat the oven to 450 degrees F (230 degrees C).

Mix 4 cloves garlic, Dijon mustard, leaves from 2 sprigs of rosemary, vinegar, 1/2 teaspoon salt, and 1/4 teaspoon pepper in a small food processor. Blend into a paste. Crush the remaining garlic.

Trim excess fat from lamb and place in a large roasting pan.

Combine tomatoes, onion, 1/4 cup honey, olive oil, remaining crushed garlic, and remaining salt and pepper in a large bowl. Mix well.

Spread rosemary-mustard paste over the top of the lamb. Spoon tomato mixture around lamb. Tuck remaining rosemary and thyme sprigs evenly up against the leg of lamb. Drizzle with remaining 1/4 cup honey.

Roast in the preheated oven for 20 minutes. Reduce oven temperature to 375 degrees F (175 degrees C). Continue roasting until an instant-read thermometer inserted into the lamb reads at least 130 degrees F (54 degrees C), 1 hour to 1 hour and 15 minutes.

Transfer lamb on a cutting board, cover with aluminum foil, and let rest, 10 to 15 minutes. Discard rosemary and thyme stems. Return the roasting pan to the oven to keep the tomato mixture warm.

Slice and arrange lamb on a plate. Spoon the warm tomato mixture and pan juices on top.