1) In a medium bowl combine the tuna, onion, parsley, olives.
2) In a small bowl, whisk together the olive oil, zest, lemon juice, salt and pepper. Pour about two thirds of the dressing over the tuna mixture and toss to combine.
3) In a separate bowl, pour the rest of the dressing over the greens and toss to combine.
4) Place some tuna salad onto each piece of wrap bread. Top with the greens and a few tomato slices. Roll the wraps and serve.