Prepare the pasta according to package directions. Cool slightly before proceeding with recipe.

In a large bowl, stir together the mayonnaise, greek yogurt and lemon juice until smooth and combined. Add sweet pickle relish, if using.

Season with salt, pepper and dill.

Toss the cooked, cooled pasta in the dressing, then add the tuna and stir to distribute well.

Add the diced celery and red onion and toss to combine.