Preheat oven to 400° F. Spray a 1-quart shallow baking pan with nonstick spray. Cut a large, deep pocket in the side of each chop with a very sharp knife.
Combine the bread crumbs, celery, onion, egg substitute, parsley, sage and pepper in a medium bowl. Fill the pocket of each chop with the mixture; skewer the edges with toothpicks to hold them together, if necessary.
Spray a large nonstick skillet with nonstick spray and set over medium heat. Add the stuffed chops and brown, turning once, until golden brown on each side.
Transfer to the prepared baking pan; cover with foil and bake until the meat is no longer pink and the vegetables in the stuffing are tender, about 10 minutes.
Remove the foil and continue baking until the stuffing is golden and slightly crispy, 10 minutes more.