1. Slice bread horizontally into five equal layers.
2. Spread bottom layer with horseradish; top with roast beef.
3. Place the next slice bread over beef; spread with mustard and top with ham or turkey and Swiss cheese.
4. Add the next slice of bread; spread with mayonnaise and top with tomato and bacon.
5. Add the next slice o bread; top with American cheese and onion. Cover with remaining bread.
6. Combine butter, sesame seeds and onion salt; brush over top and sides of loaf.
7. Place on a baking sheet; loosely tent with heavy-duty foil.
8. Bake at 400° for 15-20 minutes or until heated through. Carefully slice into 8 wedges.