In a large bowl combine beef, onion, bell pepper, mayonnaise, ketchup, salt, pepper, celery salt and egg. Measure biscuit mix into 2 qt pastry bowl; add milk and mix thoroughly with a fork.
Turn out onto a lightly floured surface. Roll or pat dough into rectangular shape about 12x18-inch. Spread beef mixture evenly over surface; roll as for jelly roll and cut into 12 slices about 1 1/2" thick.
Place in a greased baking pan. Bake at 350° F or 25 minutes. Combine 1 can soup with 2/3 cup milk in saucepan, bring to boil and serve over beef rolls.Servings: