I think tuna salad gets a bad rap. Sure, it can be mushy and flavorless. But it doesn't have to be. This recipe is very flexible and can be easily adapted to your tastes and preferences.
1 can tuna, packed in water, drained
2 hardboiled eggs, cooled and chopped
1/2 Granny Smith apple, chopped
2 Tbsp red or purple onion, finely chopped
3 Tbsp sweet pickle relish
-- OR, if you live in France: finely chopped cornichons + 1/4 tsp sugar
1/4 cup mayonnaise
1 tsp yellow mustard
1-2 Tbsp sweet pickle / cornichons juice
pinch of cinnamon (I know it's odd, but very good)
Optional add ins: chopped celery, chopped carrot, chopped cucumber...
Combine all ingredients in a bowl and mix well. Serve on crackers, dry-toasted sandwich bread or wrapped in a pita. For extra crunch, layer thin slices of Granny Smith apple on the sandwich.
NOTE: I also use this same basic recipe for egg salad. Just substitute 3 more hard boiled eggs for the can of tuna.