Stir fried vegetables in pesto with tuna, add mashed potatoes, cheese and tomatoes on top and bake. Like a shepherds pie but tuna stir fry instead of meat! What D'you think?
For my part, I don't like cooked canned tuna, but with any fresh fish this would work. Or substitute for the fish some cooked beans, such as butterbeans or soya or borlotti.