How to Make It
Season lamb with salt and pepper and place in a large bowl. Add wine, white onion, carrot, fennel bulb, and celery. Cover and transfer to refrigerator; marinate for 24 hours.
Preheat oven to 300°F. Remove lamb from marinade (reserving marinade and vegetables) and pat dry. Heat 2 tablespoons oil in a large Dutch oven over high heat. Add lamb shoulder, and sear until browned on all sides (about 5 minutes per side). Remove lamb; set aside. Transfer white onion, carrot, fennel bulb, and celery from marinade to Dutch oven and sauté until lightly browned (about 3-5 minutes). Add marinating liquid and deglaze pan. Cook over medium heat until reduced by half. Return lamb to Dutch oven. Add 3-4 quarts stock to cover lamb and bring to a boil. Add a tied bunch of thyme, bay and mint stems, cover with a tight-fitting lid and transfer to the oven. Cook until tender about 3.5 hours.
Discard vegetables and herbs from the braise. Place Dutch oven on the stove over medium heat and continue to baste the lamb while preparing clams.
Heat 2 tablespoons oil in sauté pan over medium heat. Add crushed garlic cloves and sizzle until garlic is fragrant and starts to brown. Add clams and wine. Cover and steam until all of the clams open (3-4 minutes), add ½ cup of reduced lamb jus from the braise and remove from heat.
Transfer lamb shoulder to a serving dish and top with clams. Toss red onion, pickled peppers and mint leaves to combine and scatter over the lamb and clams. Finish with lemon zest and a squeeze of lemon juice.