There are two methods of poaching, but in both cases one prime rule applies. Do not allow the liquid to boil. When poaching small fillets of fish only a small amount of liquid is needed and the resultant bouillon can be used as the base for a sauce.
When large primary ingredients are to be poached it is necessary to surround the meat or fish completely with the poaching liquid. With large fish it is advisable to place a rack on the bottom of the poaching vessel to facilitate the removal of the fish at the completion of cooking.