In a Dutch oven, melt 1 tablespoon butter over medium heat. Cook onion in butter until the onions are very soft and begin to brown. Remove from heat. Stir in apple, celery, and dried cranberries. Season with salt.
Lay each chop flat on cutting board, and with a sharp knife held parallel to the board, cut a pocket into the pork, leaving three sides intact. Stuff each chop with apple-cranberry mixture.
Melt remaining butter in the Dutch oven over medium heat. Pan-fry chops in butter for two minutes on each side. Cover, and bake in preheated oven for 45 minutes.
Transfer chops from pan to a plate, and cover with foil. Place the Dutch oven back on the stovetop over medium heat. In a small bowl or measuring cup, stir together apple juice, cornstarch, and brown sugar; pour into Dutch oven. Reduce liquid volume by half, stirring frequently. Season to taste with black pepper. Serve this apple glaze over pork chops.