In a large bowl, combine the egg, s , onion, salt and pepper. Crumble beef over mixture and mix well. Press half of the beef mixture onto the bottom and halfway up the sides of a greased 8-in. x 4-in. loaf pan. Sprinkle 3/4 cup cheese over meat to within 1/2 in. of sides. Pat remaining beef mixture over cheese.

Bake, uncovered, at 350° for 50-55 minutes or until meat is no longer pink and a meat thermometer reads 160°. Sprinkle with remaining cheese. Bake 5 minutes longer or until cheese is melted. Let stand for 10 minutes before slicing. Serve with salsa if desired. Makes 6 servings.