Step 1: Prepare the Cucumber: Wash the cucumber thoroughly. Cut it into thick slices, about 1 inch thick. Using a small melon baller or a spoon, carefully scoop out the center of each slice to create a cup, being careful not to go all the way through the bottom.
Step 2: Make the Cocktail Sauce: In a medium mixing bowl, combine the mayonnaise, ketchup, fresh lemon juice, Worcestershire sauce, salt, and black pepper. Whisk well until the sauce is smooth and evenly combined. Taste and adjust seasonings as desired.
Step 3: Combine Prawns and Sauce: Add the cooked and thawed prawns to the cocktail sauce. Gently toss the prawns until they are thoroughly coated with the sauce.
Step 4: Assemble the Cups: Carefully spoon the prawn cocktail mixture into each hollowed-out cucumber cup, filling them generously but neatly.
Step 5: Garnish and Serve: Arrange the filled cucumber cups on a serving platter. Garnish each cup with a sprinkle of fresh chopped dill or parsley. Serve immediately with lemon wedges on the side for an extra squeeze of freshness.