Preparation

• Pat the pork belly dry with paper towels. With a sharp paring knife, cut a 3/4-inch crosshatch pattern through the skin into the fat, but not through to the meat. In a small bowl, mix together 2 tsp. salt and 1 tsp. pepper, and rub onto both sides of the pork. Place on a rimmed baking sheet and refrigerate, uncovered, overnight.
• Clean the clams by soaking them in a large bowl of well-salted water in the refrigerator for 2 to 3 hours, changing the water occasionally until no sand appears at the bottom of the bowl. Remove the clams from the refrigerator and soak in fresh water for about 30 minutes before cooking.
• Let the pork sit at room temperature for about 1 hour. Position a rack in the center of the oven and heat the oven to 350°F. Place the pork, skin side up, in a 10-inch ovenproof skillet (cut to fit, if necessary). Add 1/2 cup water and bring to a simmer over medium heat. Transfer to the oven and bake, uncovered, for 45 minutes. Add another 1/2 cup water and continue to bake until the pork is fork-tender, 1 to 1-1/2 hours more. Remove from the oven and set aside.
• Put the potatoes in a 3-quart saucepan and cover with cold water. Add 1 tsp. salt, bring to a boil, then reduce to a simmer. Cook until just tender when pierced with a fork, 15 to 16 minutes. Drain and set aside.
• Combine the herbs and cream in a blender and purée until a soft whipped cream forms, about 1 minute. Set aside.
• Position a rack 6 to 8 inches from the broiler and heat the broiler (on low, if possible). Broil the pork in the skillet until the skin is puffed and crunchy, 1-1/2 to 2 minutes, rotating halfway through.
• Put the pork on a cutting board, skin side down, and set aside until cool enough to handle. Cut the pork into bite-size pieces by gently slicing through the meat with a sharp knife, then pressing the blade down firmly to cut through the hard skin.
• Heat the oil in a heavy-duty 6-quart pot over high heat until shimmering. Add the shallot and cook until just fragrant, about 1 minute. Add the clams and vermouth; cover and cook until the clams open, 5 to 10 minutes. Remove from the heat and add the potatoes, herb cream, and lemon juice. Toss and season to taste with salt and pepper. Serve the clams topped with the pork belly, and the bread on the side.