A good recipe is poached cod fillets with a lemon butter sauce. The recipe requires 1.5 lbs cod (about 4 cod fillets), 1 cup of milk, 1.5 cups of water, the juice of half a lemon and 3 tablespoons of minced shallots. The ingredients also include herbs, peppercorns, cloves and butter. Poach the fish in the milk, water and herbs; make the lemon sauce while the fish is cooking, and pour over it.
The above recipe also requires 4 tablespoons of unsalted butter, 1 bay leaf, 4 sprigs of parsley, 2 tablespoons chopped parsley, half a teaspoon of minced garlic and ground black pepper. Place the cod in one layer in the poaching pan. Add the milk and water to just cover the fish. More water can be added if required. Add bay leaf, parsley sprigs, cloves and peppercorns and cook on a gentle simmer till the fish flakes easily.
While the fish is cooking, to start the sauce, melt 1 tablespoon of butter and lightly cook the garlic and shallots in it. Add a quarter cup of the poaching liquid to the sauce mixture and bring the sauce to a boil, stirring continuously. Add the lemon juice and the rest of the butter, 1 tablespoon at a time. When the sauce is fully cooked, add minced parsley. Drain the fish, and serve it immediately with the lemon butter sauce poured over it.