My cousin and her husband owned a cafe in a big office building in Montreal and this was one of their sandwich fillers. Drain the tuna, add to that a small, peeled grated apple, a dollop of relish, a dollop of mayo and any bits of chopped up cooked ham. I usually omit the cooked ham as I find most too salty and we don't buy deli meats as a rule. If you have any gourmet relish or Bick's Dill Bits, they take the flavour up a notch.