Toss lettuce with lemon juice and divide among 4 cocktail glasses, filling them halfway. Place seafood on lettuce bed and chill in refrigerator while making sauce.
For sauce, combine cream and mayonnaise, then add tomato paste and mix until light pink. Place a spoonful of sauce over seafood and dust with cayenne and parsley. Serve with garnish of sliced lemon.
Recipe courtesy of Graham Kerr