1.Cook zucchini and carrots in a small saucepan of boiling water 1 minute; drain, refresh under cold water.
2.To make dressing, combine ingredients in a small bowl; season.
3.Place zucchini and carrots in a medium bowl with tuna, celery, onion, parsley and dressing; toss gently to combine.
4.Serve salad in lettuce leaves.
We used iceberg lettuce in this recipe as it is important to use a crisp variety of lettuce; you could also use cos (romaine) lettuce.>Note