You need to deal with the prawns in advance by rinsing them, then leaving them in a colander set over a bowl for about an hour to defrost.
After that, peel off the shells and then, using the point of a sharp knife, make a tiny slit all along the back of each prawn and remove any black thread. Now place the prawns in a bowl, sprinkle in the lime juice and Tabasco, toss them around and leave them to marinate for about 15 minutes. At this point turn the grill on to its highest setting. Meanwhile, heat the oil in a frying pan and lightly cook the onions for about 3 minutes before adding the garlic and the chillies, and continue to cook these for another 2-3 minutes. After that, divide the onion mixture between the 4 dishes, then drain the prawns and divide these equally, too.
Next, give everything a good seasoning of salt and freshly milled black pepper, then pour the cream over, followed by the cheese scattered on top. Now put the dishes on a baking sheet and place under the grill about 4 inches (10 cm) from the heat. Grill for 5-6 minutes, until the prawns turn pink and the cheese is golden brown and bubbly.