Prawn Cocktail With Avocado | Mary Berry

Ingredients

• 300g cooked peeled North Atlantic prawns, drained and dried
• 2 ripe medium avocados
• juice of 1 lemon
• 1 x 85g bag mixed lettuce leaves
• 6 large shell-on cooked king prawns
• 1 lemon cut into 6 wedges
• salt and freshly ground black pepper
• Cocktail Sauce
• 8 tbsp light mayonnaise
• 4 tbsp crème fraîche
• 6 tbsp ketchup
• 2 tbsp creamed horseradish
• 1½ tsp tomato purée
• juice of ½ lemon
• a dash of sugar