You will need
Skin the whiting. Dip your fingers in salt to get a good grip. Loosen a corner and pull firmly so the skin comes off cleanly.
Choose a shallow serving dish just large enough to take the fish in a single layer. Put a knob of butter in the dish and grill until melted.
Remove the dish from the grill and put in the fish. Turn the fish so it is buttered side up, then sprinkle with salt and pepper to taste. Grill for 2-3 minutes
Meanwhile chop the tomato finely, place in a bowl and combine with the herbs and sour cream. Add 40g of the Gruyere cheese and salt and pepper to taste and mix again.
When the fish has cooked for 3 minutes spoon the cream mixture on top, then grill for another 2 minutes until bubbling. The sauce will not be completley smooth.
Serve with a green vegetable such as French or Runner beans. Saute potatoes or Swiss Fried potatoes would also go well.
cooking for one or two