Cook the shells according to package instructions, being sure not to over cook. Drain and rinse with cold water.
1 pound medium shells
In a small bowl, whisk together the mayonnaise, yogurt, lemon juice, dill, salt and pepper.
1 cup light mayonnaise, 1/4 cup plain yogurt, 1 teaspoon lemon juice, 1 tablespoon fresh dill, 1 teaspoon salt, 1/4 teaspoon black pepper
Add the noodles, tuna, peas, celery, and onion to a large bowl. Pour dressing over it, and toss to combine.
12 ounces tuna, 1 cup frozen peas, 2 stalks celery, 1/2 small red onion