Cook the pasta according to the directions on the box. When done, drain, rinse with cold water, and drain again.
Mix the chopped veggies, peas and drained tuna in a large bowl
Mix the mayo, yogurt, lemon juice, dill weed, celery salt, salt & pepper together in a small bowl
Add the cooked and cooled pasta to the large bowl and stir through.
Add half of the dressing to the large bowl and stir through.
Refrigerate both the salad and the remaining dressing for 1-2 hours.
Before serving, stir the remainder of the dressing through the salad to freshen it up. Taste and adjust for salt and pepper.
Garnish with parsley and small tomatoes.