Preheat your oven to 350 degrees F and line a roasting pan with aluminum foil.
Dry the leg of lamb thoroughly using paper towels and create shallow diamond-shaped cuts on the top side using a sharp knife.
Mix minced garlic, olive oil, chopped rosemary and thyme, Dijon mustard, salt, and pepper in a small bowl.
Position the lamb, fat side up, on a rack in the prepared roasting pan.
Evenly spread the garlic mixture over the lamb, ensuring it's well incorporated into the scored cuts.
Roast the lamb in the oven until it reaches an internal temperature of 135 degrees F for medium doneness, which usually takes around 1 hour 30 minutes to 1 hour 45 minutes.
Allow the lamb to rest for 15 minutes before carving.
Serve alongside mini hasselback potatoes.
10 servings