Pulled Pork Sandwich

Pat 900 g pork shoulder dry and rub it evenly with 1 teaspoon salt and 1 tablespoon paprika. Thinly slice 150 g onion, lightly crush 3 garlic cloves, and let the seasoned meat stand for 20 minutes. Cover the bottom of a heavy pot with the onion and garlic, then set the pork on top. Pour 200 ml water around the edge of the pot rather than over the meat, preserving the spice coating. Cover and cook gently over low heat. Check the liquid on the bottom every 30 minutes, adding only a small splash of water if the onions begin to stick or darken too far. After a total of 2.5 to 3 hours, press the pork with a fork. If the fibers still resist, cook for another 20 minutes instead of forcing firm meat apart. Remove it from the pot and cool for 5 minutes, then use two forks to pull it along its natural grain. Stir 1 cup barbecue sauce into the softened onions and cooking juices left in the pot, and fold the shredded pork back in. Warm everything over low heat for about 3 minutes so the sauce reaches between the strands rather than sitting only on their surface. Lightly toast the cut faces of 4 burger buns before filling them, which slows the sauce from soaking into the crumb. The pork can also be made a day ahead and reheated gently with its sauce before assembly.