1In a small mixing bowl combine egg, crumbs, Worcestershire sauce and dash of pepper. Add beef; mix well. Shape into two 1/2-inch thick patties.
2Place in a microwave-safe 10-by 6-by 2-inch baking dish. Cover loosely with wax paper. Cook with 650 watts for 2 minutes, giving dish a half-turn once. Turn patties over. Cook, covered, with 650 watts for 1 to 2 minutes more or until done.
3Remove patties, reserving drippings in dish. Keep patties warm. Skim fat from drippings. Add onion, celery, gravy mix and pepper to drippings. Stir in water. Cook, uncovered, with 650 watts for 3 to 4 minutes or until thickened and bubbly, stirring every minute. Serve gravy over patties.