Slow-Roasted Pork with Red Cabbage, Jalapeños, and Mustard

Preheat the oven to 250 degrees F. Combine the caraway, cloves, star anise, and peppercorns in a spice grinder and process until they have the coarseness of salt. Combine the spices with the salt. Rub the pork vigorously with the spice mixture until completely covered. Any spice mixture that doesn't stick to the meat can be removed. Place the meat in a roasting pan, cover tightly, and cook in the oven for about 4 hours. The meat should be fork-tender and some of the fat should have rendered into the bottom of the pan. Transfer the meat to a plate and discard the fat from the pan. Increase the oven heat to 350 degrees F. In a bowl, combine the cabbage, oil, and vinegar and season generously with salt and pepper. The cabbage should taste quite salty and tangy. Slice the ciabatta rolls in half. Spread the mustard evenly across the bottom halves. Using a couple of forks, pull the roasted pork apart and distribute some on the bottom and top halves. Place the bread in the oven and remove when the bread is lightly toasted and the meat is heated through. Add the cabbage on the bottom halves and top with the jalapeño. Close the sandwiches, cut into halves, and serve.