Prep Shrimp: Peel and devein shrimp, or if they are already peeled and deveined, take them out of the fridge while the water comes to a boil.
Boil Water: Add 8 cups of water to a medium to large sized pot and heat on high. Cut the fresh lemon in half and squeeze the lemon juice from both halves of the lemon into the pot.
Boil Shrimp: Once the water comes to a boil, add 1 tablespoon of Old Bay Seasoning to the water. Add the shrimp to the water and cook for 3 minutes or until the shrimp is opaque (white or pearly pink) and it has curled into a "C" shape.
Drain: Immediately drain the shrimp, shake off excess liquid, and add to a large cutting board and spread it all out to cool slightly.
Make Dressing: While the shrimp cools, add the mayonnaise, vinegar, lemon juice, dill, and pepper to a small mixing bowl and mix until it is all well combined.
Chop Shrimp: Roughly chop the shrimp into bite sized pieces (or smaller if desired) and then add them to a large mixing bowl.
Mix Salad: Add celery, onion, and shallots to the large bowl with the chopped shrimp and mix. Add the mayo dressing and mix to coat all of the shrimp with the dressing.
Chill: Cover the bowl and chill it in the fridge to chill for at least 30 minutes.
Serve and Enjoy! Garnish with a little more fresh chopped dill and serve and enjoy with crackers, on lettuce, or on crostini!