Fill a large pot with water and bring it to a rolling boil over high heat. Add a squeeze of lemon juice along with a few lemon halves for extra flavor. This simple step infuses the shrimp with a subtle citrus note as it cooks.
Turn off the heat as soon as the water boils, then drop the shrimp straight in. Let them sit in the hot water for about three minutes, no stirring needed. This gentle method keeps the shrimp from overcooking or turning tough.
Use a slotted spoon to lift the shrimp out and spread them on a plate. Pop the plate in the fridge for a few minutes to cool them quickly. Cooling the shrimp before mixing keeps the mayo dressing from turning watery.
While the shrimp cools, dice your bell pepper and celery into small, even pieces. Slice the green onion thinly so it blends smoothly into every bite. Keeping the pieces small helps the salad hold together nicely on a fork or cracker.
In a large bowl, stir together the mayonnaise, lemon juice, dill, salt, and pepper. Whisk it until it looks smooth and creamy with no lumps. This dressing is the heart of the recipe, so taste it before moving on.
Add the cooled shrimp, bell pepper, celery, and green onion into the bowl with the dressing. Gently fold everything together so the shrimp stays intact instead of breaking apart. A light hand here keeps the texture of the salad looking appealing.
Cover the bowl and refrigerate the salad for at least one hour before serving. This resting time lets the flavors soak into the shrimp and vegetables. If you're short on time, you can eat it right away, but the wait truly makes a difference.