Begin by filling a medium saucepan with water and adding a generous amount of salt. Bring to a gentle simmer and add the shrimp, cooking for 2-3 minutes until pink and opaque.

Transfer the cooked shrimp to an ice bath to halt cooking, ensuring they remain tender.

In a mixing bowl, combine mayonnaise, lemon juice, Dijon mustard, dill, salt, and pepper. Whisk until smooth and creamy, adjusting seasoning.

In a large bowl, add the poached shrimp, diced celery, and minced red onion. Toss gently and gradually add the dressing.

Cover and refrigerate for at least 30 minutes to let the flavors meld.

Serve the shrimp salad over mixed greens, in croissants, or in lettuce cups.