Prawn Cocktail!!!

Bahan-bahan (6 porsi)

• 1 kg / 2 lb medium fresh cooked or raw prawns with shell and heads on ((yields ~600g once peeled); OR)
• 600 g / 1.2 lb fresh cooked prawns already peeled
• About 3 cup iceberg lettuce, finely sliced
• Lemon wedges
• Finely chopped parsley ((optional))
• 2/3 cup / 165 ml mayonnaise (, preferably good quality whole egg mayonnaise (Note 2))
• 1 tbsp ketchup (or Australian/UK tomato sauce (Note 3))
• 1 tsp Worcestershire sauce
• 1 tsp freshly grated horseradish ((or sub 1 1/2 tsp jarred OR 3/4 tsp wasabi))
• Dash of tabasco sauce ((to taste))
• Pinch of cayenne pepper ((to taste + tiny bit of colour))