Combine tuna salad: add tuna, celery, red onion, dill or parsley, Dijon mustard, lemon juice, pickles, garlic powder, and Greek yogurt or mayonnaise to a bowl. Mix until creamy.
2 cans, 3 tablespoon red onion, 1 tablespoon fresh dill or parsley, 1 tablespoon Dijon mustard, 2 tablespoon lemon juice, 3 tablespoon pickles, ⅓ cup Greek yogurt or mayonnaise, ½ teaspoon garlic powder, 2 celery stalks