My rules are similar for hamburgers. On the top bun must be ketchup, pickles, and cheese. On the bottom must be mustard and lettuce, and if we have it, tomato. Basically, I don't want two yellow things together (mustard and cheese), two green things (pickles and lettuce), two red things (ketchup and tomato), or two sour things (mustard and pickles). I can eat a wrong burger, but I prefer it the right way.