Add 2 quarts of water to a large pot and place it on the stove over high heat. Squeeze a little lemon juice into the water and drop the lemon halves into the pot. Add the garlic, bay leaf, pepper, salt, and Cajun seasoning. Bring the liquid to a rolling boil.

Once the water reaches a rolling boil, remove the pot from the heat and immediately submerge the shrimp into the hot water. Poach them for three minutes.

Using tongs or a slotted spoon, carefully transfer the cooked shrimp to a plate. Allow them to cool by placing them in the refrigerator.

Once the shrimp have cooled, place them in a large bowl with the bell pepper, celery, green onion, mayonnaise, lemon juice, dill, salt, and pepper.

Gently mix the ingredients until they are well combined.

Allow the salad to sit in the refrigerator for at least one hour before serving, which allows the flavors to marinate and develop.