Mix your tuna with the mayo.

Chop the dill pickle (amount is your preference), and mix with the tuna.

Butter 2 slices of bread. Place one slice of bread, butter side down, in a fry pan, on medium heat. Spread some tuna mixture on top of that slice of bread, and top with slices of cheese, and other slice of bread.

Flip the sandwich over, when the bottom is golden.