A snack with pickles, onions, and fat-free Greek yogurt.
Lightly toast muffin halves. Set aside on a baking sheet lightly sprayed with nonstick spray.
In a small bowl, combine tuna, dijonnaise, yogurt, pickle, onion, lemon juice, garlic powder, and pepper. Mix well.
Evenly distribute tuna mixture between the muffin halves. Top each with a slice of tomato followed by a slice of cheese.
Broil for 1 to 2 minutes, until cheese melts.
Feel free to use fat-free mayo instead of Greek yogurt.