1 1/2 lb. ground beef
1/2 c. soft bread crumbs
1 egg, beaten
1 tbsp. mustard
1/8 tsp. pepper
6 oz. sliced mozzarella cheese
1 tsp. oregano
1 c. ketchup
1 c. water
1 tbsp. worcestershire sauce

Mix beef, crumbs, egg, mustard and pepper. Pat into a 10 x 14 inch rectangle on waxed paper. Place cheese slices on the mixture. Sprinkle with oregano. Roll tightly as for a jelly roll, starting at short end, lifting paper with one hand. Press ends to seal. Transfer to a shallow baking dish, seam side down. Combine ketchup, water, and sauce. Pour over beef. Bake at 375 degrees for 1 hour and 10 minutes, basting once or twice. Serve with sauce.