In a wide pot or deep skillet combine 6 cups water, 1 tablespoon kosher salt, 1 teaspoon whole black peppercorns, and 1 bay leaf. Slice the lemon in half and squeeze the juice into the pot, then drop the squeezed halves in as well. Bring the mixture to a gentle simmer over medium heat (do not boil hard).

Poach shrimp

When the liquid is simmering, add the peeled and deveined shrimp in a single layer. Cook just until the shrimp turn pink and opaque and curl into a loose 'C' shape — about 2 to 3 minutes depending on size. Do not overcook.

Shock shrimp

Prepare an ice bath by filling a large bowl with 4 cups ice and cold water. Using a slotted spoon, transfer the cooked shrimp immediately to the ice bath to stop cooking. Leave them in the ice bath for 3 minutes or until completely cool.

Drain and chill

Drain shrimp well on paper towels or a rack. Pat dry gently and refrigerate until ready to serve (at least 15 minutes) — keep tails on for presentation.

House-made Cocktail Sauce

Combine 1 cup ketchup, 3 tablespoons prepared horseradish, 2 teaspoons fresh lemon juice, 1 teaspoon Worcestershire sauce, 1 teaspoon hot sauce, 1 teaspoon smoked paprika, 1 teaspoon kosher salt, and 1 teaspoon black pepper in a small bowl.

Whisk thoroughly to a uniform sauce. Taste and adjust: add more horseradish for heat, more lemon for brightness, or a pinch more salt if needed. Chill the sauce in the refrigerator for at least 15 minutes to allow flavors to meld.

Garnish & Serve

On a serving platter or individual plates, create a bed of crushed ice (use the 4 cups reserved for serving). Arrange chilled shrimp around a small bowl of cocktail sauce, tail ends facing out for easy picking.

Garnish with lemon wedges and sprinkle chopped parsley over the shrimp. Serve immediately with extra lemon wedges and additional sauce on the side if desired.