In a large pot, combine 2 quarts of water with lemon halves, minced garlic, a bay leaf, sea salt, and optional Cajun seasoning. Bring to a boil.

Carefully submerge the raw shrimp and poach for about 3 minutes until pink and opaque. Transfer to a plate to cool.

In a mixing bowl, combine the cooled shrimp, red bell pepper, celery, green onion, mayonnaise, lemon juice, dill, salt, and pepper. Fold together gently.

Cover and refrigerate for at least 1 hour before serving to meld flavors.

Serve in lettuce cups, on crackers, or in a sandwich.