Cook noodles according to package instructions, until al dente. Drain.

In a large bowl add chopped onion and celery, peas, cooked pasta, and drained tuna.

In a separate bowl, mix the mayo and Greek yogurt.

Stir half of the sauce into the pasta mixture and toss to evenly coat. Season with salt and pepper and dried dil, to taste.

Refrigerate pasta and remaining sauce separately, covered, for 30 min. Stir in remaining sauce and serve immediately.