Preheat your oven to 325°F (160°C).

In a mixing bowl, combine olive oil, minced garlic, chopped rosemary, lemon juice, salt, and pepper.

Generously coat the lamb with the marinade and let it marinate for 2–4 hours, ideally overnight.

Remove the lamb from the refrigerator and let it sit at room temperature for 30 minutes.

Place the marinated lamb in a roasting pan. Add vegetables if desired.

Roast the lamb uncovered for the first 1.5 hours.

Check for doneness about 30 minutes before the end, aiming for an internal temperature of 135°F (medium-rare) or 145°F (medium).

Let the lamb rest for 20 minutes after removing it from the oven.

Slice the lamb against the grain and serve.