Creating Oven-Roasted Lamb Shoulder with Herb Sauce is straightforward when you follow these steps:

1. Prepare the Marinade: In a bowl, mix minced garlic, rosemary, thyme, parsley, olive oil, salt, pepper, lemon zest, and lemon juice.
2. Marinate the Lamb: Rub the marinade all over the lamb shoulder, ensuring it’s well-coated. Cover and refrigerate for at least 1 hour, or overnight for more flavor.
3. Preheat the Oven: Preheat your oven to 325°F (165°C).
4. Prepare the Roasting Pan: Place the marinated lamb shoulder in a roasting pan. Pour the broth and white wine (if using) around the lamb.
5. Roast the Lamb: Cover the pan with foil and roast in the preheated oven for 3 hours. Remove the foil and continue roasting for an additional hour, basting occasionally.
6. Check for Doneness: The lamb is done when its internal temperature reaches 145°F (63°C) for medium-rare or 160°F (71°C) for medium.
7. Rest the Lamb: Once cooked, remove the lamb from the oven and let it rest for 15-20 minutes before carving.
8. Prepare the Herb Sauce: While the lamb rests, combine parsley, mint, capers, garlic, lemon zest, and olive oil in a bowl. Mix well and season with salt and pepper to taste.
9. Carve the Lamb: Use a sharp knife to slice the lamb shoulder into thick pieces.
10. Serve: Drizzle the herb sauce over the sliced lamb or serve it on the side.