"The best thing you could possibly do with a can of tuna...."
mayonnaise
Juice of 1/2 lemon
crushed red pepper flakes (optional)
(6-oz.) cans tuna
ribs celery, finely chopped
dill pickles, finely chopped
finely chopped red onion
freshly chopped parsley
Kosher salt
Freshly ground black pepper
slices bread, such as sourdough
butter
tomato, sliced
slices cheddar