
Prepare the salsa verde: Combine parsley, basil, capers, garlic, anchovy paste (or salt), red pepper flakes, black pepper, olive oil, and red wine vinegar in a small bowl and stir well.
In a medium bowl, combine cannellini beans, cherry tomatoes, torn olives, and red onion. Sprinkle with kosher salt and toss gently.
Drizzle the salsa verde over the salad mixture and toss carefully.
Add parmesan shavings and mix lightly.
Top with tuna if using, and serve with crusty bread.