Adapted from The Book of Jewish Food by Claudia Roden
2 pounds halibut fillets
Salt and pepper
2 tablespoons extra virgin olive oil
Juice of 1 lemon
2 eggs
3 tablespoons finely chopped flat-leafed parsley
Put the fish in a pan that can accommodate it in one layer. Pour just enough water to cover. Add salt, pepper, oil and half the lemon juice. Bring slowly to a boil and poach very gently, so the surface of the water barely trembles, for 5 to 10 minutes until the flesh of the fish just begins to flake. Lift the fish out carefully and arrange on a serving dish, leaving the water in the pan. There should be about 1 cup of liquid left.
To make the sauce, beat the eggs with the rest of the lemon juice, then beat in a few tablespoons of the cooking water into it. Now pour this mixture into the pan with the hot cooking water and stir constantly over a very low flame until it thickens. Do not let it boil. Add the parsley. Pour over the fish and refrigerate, covered with plastic wrap.
Note: for a thicker sauce, mix 1 tablespoon of cornstarch with a little water to form a paste, then stir into the cooking water and simmer for 10 minutes before adding the beaten-egg mixture.