Creating a succulent roast lamb can be straightforward if you follow these steps:

1. Prepare the Marinade: In a bowl, combine minced garlic, rosemary, thyme, lemon zest, lemon juice, olive oil, salt, and pepper.
2. Marinate the Lamb: Rub the marinade all over the leg of lamb. Cover it with plastic wrap and refrigerate for at least 1-2 hours, preferably overnight.
3. Preheat the Oven: Preheat your oven to 375°F (190°C).
4. Prepare the Vegetables: If using, chop the vegetables into even pieces. Place them in a roasting pan to create a bed for the lamb.
5. Place the Lamb: Remove the lamb from the marinade and place it on top of the vegetables in the roasting pan.
6. Roast the Lamb: Place the pan in the preheated oven and roast for 1.5 to 2 hours, or until the internal temperature reaches 135°F (57°C) for medium-rare.
7. Baste Occasionally: Every 30 minutes, baste the lamb with the pan juices to keep it moist and flavorful.
8. Check Doneness: Use a meat thermometer to check for desired doneness. For medium, aim for 145°F (63°C).
9. Rest the Lamb: Once cooked, remove the lamb from the oven and let it rest for 15-20 minutes before carving.
10. Carve and Serve: Slice the lamb against the grain and serve it on a platter with the roasted vegetables.

These steps will guide you in creating an incredible roast lamb that will impress everyone at your table.