A delicate way of serving this rather rich fish, Mackerel with Lemon and Caper Sauce is perfect for a light meal.
4 mackerel, cleaned and filleted
3 fl. oz. lemon juice H oz. butter
1 tablespoon flour
10 fl. oz. fish stock
1 teaspoon salt
1 teaspoon white pepper
½ teaspoon chopped fresh tarragon
2 egg yolks, lightly beaten
2 tablespoons double cream v tablespoon capers
Place the mackerel fillets in a shallow dish. Sprinkle over 4 tablespoons of the lemon juice. Set aside.
In a medium-sized saucepan, melt J ounce of the butter over moderate heat. Remove the pan from the heat and, with a wooden spoon, stir in the flour to make a smooth paste. Gradually add the stock, stirring constantly. Return the pan to the heat and cook, stirring, for 2 to 3 minutes or until the sauce is thick and smooth.
Stir in the remaining lemon juice, half the salt, half the pepper and the tarragon. Reduce the heat to very low and, using a wire whisk, beat in the egg yolks and the cream. Stir in the capers.
Cook for 10 minutes, stirring occasion-ally, being careful not to let the sauce come to the boil. Remove the pan from the heat. Set aside and keep hot.
Preheat the grill to high. Remove the fish fillets from the dish and dry them with kitchen paper towels. Place them on a wooden board and rub the remaining salt and pepper all over them. Place the fillets on the rack in the grill pan and dot with the remaining butter. Put the grill pan under the heat and cook the fish for 5 minutes on each side, or until it flakes easily when tested with a fork.
Remove the pan from under the heat. With a fish slice or spatula, transfer the mackerel fillets to a heated serving dish.
Pour the sauce over the fish and serve immediately.