If you’re using tuna packed in water, drain it before using. If your tuna is packed in olive oil, there is no need to drain. In a bowl, combine the tuna, cannellini beans, pepperoncinis, red onion, capers, and parsley. Add the olive oil and lemon juice and season to taste with salt and pepper. Serve on a bed of greens with tomatoes on the side and crackers for scooping.