1. Start oven, set at Moderate, 350° F. Rub a shallow baking dish with a little ham fat.
2. Trim the rinds from the ham slices, notch the fat, brown the slices on 1 side in a hot frying pan.
3. Mix the crumbs, celery, onion, salt and pepper. Spread half of this mixture on each ham slice, covering the unbrowned side. Roll them up, tie with kitchen twine (dipped in hot water), place in the baking dish and pour the tomato juice over them.
4. Bake 1 hour, basting several times with the liquid in the pan.
5. Remove to a warmed serving platter, remove string and discard it and cut each roll into 3 serving pieces.