Cook 8 ounces pasta shells, according to the package directions. Drain and rinse in cold water, cover, and place in the fridge to cool down.
To a large bowl, add the cooled pasta, 10 ounces cherry tomatoes,1 cup frozen peas, ¼ cup red onion, and 10 ounces canned tuna,. Toss to combine.
In a smaller bowl, whisk together ½ cup mayonnaise, ½ cup Greek yogurt, 2 tablespoons parsley,1 tablespoon dried dill, 1 tablespoon lemon juice, and salt and pepper to taste.
Pour the dressing over the salad and toss to coat. Enjoy right away or cover and refrigerate anywhere from 1 hour to overnight before serving.