Prepare the Flavor Base: In the medium mixing bowl, combine the minced garlic, lemon zest, the reserved 1 tablespoon of oil from the sun-dried tomatoes, and the freshly ground black pepper. Whisk briefly and set aside for 5-10 minutes to allow the garlic to infuse the oil.
Create the Creamy Bean Emulsion : Add approximately half of the rinsed and drained cannellini beans to the bowl with the infused oil. Using the back of a fork, mash the beans thoroughly against the side of the bowl until they form a coarse, thick paste. This will serve as the creamy, binding element for the dressing.
Whisk the Lemon-Dill Vinaigrette : To the mashed bean mixture, add the Greek yogurt and lemon juice. Whisk vigorously until the ingredients are fully combined into a smooth, creamy vinaigrette. Stir in the chopped fresh dill and parsley.
Build the Salad Foundation : Drain the olive oil from the cans of tuna into a separate container (you can reserve it for another use). In the large mixing bowl, gently flake the tuna with a fork, leaving some larger, satisfying chunks.
Incorporate the Vegetables and Beans : To the flaked tuna, add the remaining whole cannellini beans, the diced red bell pepper, diced celery, chopped sun-dried tomatoes, and the thoroughly rinsed capers. Gently toss to combine.
Dress and Fold : Pour the creamy vinaigrette from the medium bowl over the tuna mixture. Using a silicone spatula, gently fold everything together until every ingredient is evenly coated. Avoid over-mixing to maintain the chunky texture of the tuna.
Serve or Chill : For the best flavor, let the salad rest in the refrigerator for at least 15 minutes to allow the flavors to meld. Serve chilled on a bed of arugula, in a whole-wheat pita, or with whole-grain crackers.