Make sure the prawns are drained well of their briny liquid.
Mix the salad cream, ketchup, lemon juice and Tabasco in a bowl.
Tip in the prawns and mix to coat them in the Marie-Rose sauce.
Finally shred the lettuce, and arrange as a bed on six small plates or shallow bowls.
Divide the prawns in their sauce on the centre of each plate in a kind of pyramid, and then scatter with roughly crushed peppercorns or dust with paprika.
As long as the prawns were properly thawed and drained before you started immersing them in their famous coral pink sauce, it does not matter if they sit for a good few hours in the fridge before being dolloped out onto their lettuce-lined dishes.