Hollandaise is the mother of all the warm emulsion sauces. The version we use here is easy to make and quite delicious with fish. Like Mayonnaise it takes less than 5 minutes to make and transforms any fish into a feast. Once the sauce is made it must be kept warm: the temperature should not go above 70-80C / 180F or the sauce will curdle. A thermos flask can provide a simple solution on a small scale, otherwise put the Hollandaise Sauce into a delph or plastic bowl in a saucepan of hot but not simmering water. Hollandaise Sauce cannot be reheated absolutely successfully so it’s best to make just the quantity you need. If however you have a little left over, use it to enrich other sauces or mashed potato.
Serves 4-6, depending on what it is to be served with
2 egg yolks, preferably free-range and organic
110g (4ozs/1 stick) butter cut into dice
1 dessertspoon (2 American teaspoons) cold water
1 teaspoon freshly squeezed lemon juice, approx.
Put the egg yolks in a heavy stainless saucepan on a low heat, or in a bowl over hot water. Add water and whisk thoroughly. Add the butter bit by bit, whisking all the time. As soon as one piece melts, add the next piece. The mixture will gradually thicken, but if it shows signs of becoming too thick or slightly scrambling, remove from the heat immediately and add a little cold water if necessary. Do not leave the pan or stop whisking until the sauce is made. Finally add the lemon juice to taste. If the sauce is slow to thicken it may be because you are excessively cautious and the heat is too low. Increase the heat slightly and continue to whisk until the sauce thickens to coating consistency.
It is important to remember that if you are making Hollandaise Sauce in a saucepan directly over the heat, it should be possible to put your hand on the side of the saucepan at any stage. If the saucepan feels too hot for your hand it is also too hot for the sauce.
Another good tip if you are making Hollandaise Sauce for the first time is to keep a bowl of cold water close by so you can plunge the bottom of the saucepan into it if becomes too hot.
Keep the sauce warm until service either in a pyrex bowl over hot but not simmering water (do not have gas jet on). A thermos flask is also a good option.
Hollandaise Sauce is best served with poached fish not pan-fried or pan-grilled fish.