Place the fillets in a shallow pan and moisten with a little wine or fish stock, water will do if you don't have anything else. There should only be sufficient liquid to keep the fish from frying, the fillets will produce their own liquid during the cooking process.
Cook over a low heat for around 5 minutes and remove just before the fish are fully cooked - fish always continues to cook a little on its own after being taken off the heat.
Reduce the cooking liquor and add flavours you enjoy; keep them subtle otherwise they will over power the delicate flavour of the fish.
Add a little butter, cream or olive oil to the liquor just before serving to enrich the sauce.
Knorr offer a liquid fish stock that is ideal for fish cookery if you have no fresh stock.