In a medium mixing bowl, combine the finely chopped tomatoes, flaked tuna, coarsely chopped hard-boiled eggs, sliced red onion, chopped red bell pepper, chopped olives, minced garlic, and fresh parsley.

In a separate small bowl, whisk together the extra-virgin olive oil, white wine vinegar, water, salt, and black pepper to create the dressing.

Gently fold the dressing into the tomato, tuna, egg, onion, pepper, olive, garlic, and parsley mixture until thoroughly combined.

Cover the bowl and refrigerate the salad for at least 2 hours before serving to allow the flavors to meld together.