Also, cheese

The proper order of a grilled tuna sandwich goes like this: bread, cheese, tuna, cheese, bread.

Why?

1. Because if you just put cheese on one side, the other side of the bread has nothing to grab on to. This could create a potential mess and nobody wants a mess.

2. More importantly, if I have to give you a reason why you should add more cheese to something I might find it difficult to remain your friend.