Preparation

Make the pork belly

• In a medium bowl, combine the salt, sugar, fennel seeds, chile flakes, and nutmeg. Rub the raw garlic halves over the pork and discard. Sprinkle the spice mixture over the pork to coat well. Transfer to a large sealable bag (or a covered roasting dish) to marinate in the refrigerator overnight or up to 24 hours.
• An hour before roasting, remove the pork belly from the refrigerator to bring up to room temperature.
• Preheat the oven to 275°F.
• Place the belly in a shallow roasting pan, meat-side down, and brush the top with the molasses. Place a piece of parchment paper over the meat and cover the pan tightly with foil. Roast until fork-tender, about 3 hours.

Make the sandwiches

• Heat a panini grill or large cast-iron skillet until hot. Using a sharp knife, cut the pork crosswise into six 1⁄4-inch-thick slices, then cut each slice in half, reserving the remaining pork belly for another use.
• Open the buns and spread or squirt about 1-1⁄2 tsp. mayonnaise and 1 tsp. mustard over each half. Drizzle with a few dashes of hot sauce and sprinkle with salt. On each bottom half, layer slices of cheese, ham, pork belly, and pickles. Cover with the tops and brush the outside of each bun with melted butter.
• In batches, place the filled buns in the panini grill, pressing down to flatten them slightly. If using a cast-iron skillet, put another heavy skillet or weight on top to flatten them and turn them over after 2 or 3 minutes. Grill until golden brown. Serve immediately.