certain toppings really lend themselves to that flavor combination--pepperoni, for example--but there are certain foods that really just don't jibe with pizza.
...
things you shouldn't put on pizza
- canned tuna. (flickr/ paolovalde) ...
- kimchi. (flickr/emkeller) ...
- uni and other raw seafood. (arthur bovino) ...
- lettuce. (flickr/avlxyz)