Step 1: Prepare the Shrimp: Bring a large pot of salted water to a boil. Add the shrimp and cook for about 2-3 minutes, or until they turn pink and opaque. Remove from heat, drain, and immediately transfer to an ice bath to stop the cooking process. Once cooled, drain and pat dry.
Step 2: Prepare the Mussels: In a separate pot, bring water to a boil. Add the cleaned mussels and cover. Steam for about 5-7 minutes, or until the mussels open. Discard any that remain closed. Let cool slightly and remove from shells if desired.
Step 3: Prepare the Scallops (optional): Sear them in a hot skillet with a little olive oil for about 2-3 minutes on each side until golden brown. Remove from heat and let cool.
Step 4: Make the Cocktail Sauce: In a bowl, combine the ketchup, horseradish, Worcestershire sauce, lemon juice, salt, and pepper. Mix well and adjust seasoning to taste. If you like it spicy, add a few dashes of hot sauce.
Step 5: Assemble the Platter: On a large serving platter or board, arrange the seafood artistically. Place the shrimp, crab meat, mussels, and scallops in separate sections or clusters.
Step 6: Garnish and Serve: Add lemon wedges and sprinkle with fresh parsley or dill for garnish. Serve the cocktail sauce in a small bowl in the center or alongside the seafood. Serve chilled or at room temperature.