Heat the olive oil in a large frying pan with 15g (1/2oz) (1 tbsp) of the butter. Once the butter has stopped sizzling add the chilli and garlic and sauté for about 30 seconds until the garlic is lightly golden.
Tip the prawns or shrimps into the pan and sauté for another few minutes until tender. The prawns will change in colour and begin to curl. Be careful not to overcook. Add the rest of the butter with a good squeeze of lemon juice and swirl the pan to make a sauce. Sprinkle over the parsley, tossing to coat. Season to taste.
To serve, divide the sizzling prawns among warmed dishes with all of their delicious juices. Serve at once with plenty of crusty bread.