I first had this very simple tuna and white bean salad at Chef Carla Pellegrino’s Neapolitan restaurant, Bratalian.   It was so delicious that I had to ask the manager what was in it.  I was shocked to learn that the simplest ingredients: lemon, olive oil, salt and pepper, were what made it so good!  After having it at the restaurant, I set out to recreate the dish and now it’s a weekday staple dinner for us.  The base of the salad is peppery arugula dressed with a drizzle of olive oil, fresh lemon juice, salt and freshly ground black pepper.  The main part of the salad is juicy grilled tuna paired with creamy cannellini beans, crisp red onion and celery. This salad is crazy-good and amazingly simple to make.  I usually use canned whole white albacore tuna for this dish, but today I used fresh tuna, because I had a thought that it would be even more amazing–and it did not disappoint.  I think from now on I will use fresh tuna whenever possible. …