01 - Fill a medium saucepan with water and add sea salt and lemon slices. Bring to a boil over high heat.
02 - Add shrimp to the boiling water and cook for 2-3 minutes until shrimp turn pink and are just cooked through. Do not overcook.
03 - Immediately transfer shrimp to a bowl of ice water to stop cooking process. Let chill for at least 5 minutes, then drain well.
04 - In a small bowl, whisk together ketchup, horseradish, lemon juice, Worcestershire sauce, hot sauce, and black pepper. Adjust seasoning to taste.
05 - Arrange chilled shrimp on a serving platter or in cocktail glasses. Serve with cocktail sauce, lemon wedges, and garnish with fresh parsley or dill sprigs.