Begin by filling a large pot with 2 quarts of water and adding the lemon halves, smashed garlic, bay leaf, sea salt, black pepper, and optional Cajun seasoning. Bring this mixture to a boil over medium-high heat.

Once boiling, remove the pot from heat, submerge the raw shrimp, and let them poach in the hot liquid for 3 minutes until they turn pink and opaque. Transfer the shrimp to a plate to cool, then refrigerate them until needed.

In a large mixing bowl, combine the cooled shrimp with the diced red bell pepper, finely chopped celery, and sliced green onions. Next, add the creamy mayonnaise, fresh lemon juice, chopped dill, sea salt, and black pepper. Gently fold these ingredients together until well incorporated.

Cover the bowl with plastic wrap or a lid, and place it in the refrigerator. Allow the shrimp salad to chill for at least 1 hour.

Plate the salad elegantly or use it as a filling for lettuce wraps. Garnish with extra dill or a sprinkle of black pepper to serve.