First, you have to start by making the sauce, which is one of the main ingredients in a spicy prawn cocktail. Take a medium bowl and combine the mayonnaise and sweet chilli sauce in this. Then, add the tomato sauce/ketchup, lime juice, and half the lime leaves to it, and mix them in properly. Now, set this aside.
Next, divide the shredded iceberg lettuce evenly between the eight large bar glasses – this will serve as the bottom layer in the prawn cocktail.
Then, scatter the diced avocados over the lettuce bed, and follow it up by evenly distributing the prawns between all eight glasses. Make sure the prawns you use have been peeled, deveined, and cooked properly – overcooking will make them tough and rubbery, while undercooking them will lead to an unpleasant, slimy texture.
For the finishing touch, use a spoon to add a large dollop of the sauce to each serving, and then top the glasses with the remaining shredded lime leaves. Finally, fix a lime wedge onto the rim of each glass, as a fresh garnish.