This hollandaise sauce may be prepared in advance and, according to my mother, cannot fail. Unless, of course, you overheat it, in which case it will certainly separate. But if you follow the recipe to the letter, you will find that hollandaise — one of the glories of the French repertoire — does not deserve it’s reputation as a sauce that only professional chefs can make.
The recipe makes about a cup of sauce.
3 egg yolks
4 oz. (125 g.) unsalted butter (1 stick)
juice of 1/2 lemon
2 tsp. boiling water
1/4 tsp. salt
freshly ground black pepper
In a bowl, whisk the egg yolks until well-blended, about 20 seconds. Add the salt and whisk.
Melt the butter in a small saucepan. In a second small saucepan, heat the lemon juice to lukewarm. In a third saucepan, heat a small quantity of water to boiling.
Begin adding the melted butter to the bowlful of yolks, teaspoonful by teaspoonful, whisking constantly. The bowl should not be on the heat, but keep it close to the stove so that it will be warm. When the sauce begins to thicken, add a few drops of the lemon juice.
Continue in this way, back and forth between butter and lemon, until all the butter and juice has been incorporated. Stir in the boiling water.
Grind in some pepper and taste to check the flavorings, adding more salt or lemon juice as necessary.
If serving within the hour, place the bowl in a warm place, for example beside the stove.
If serving later, place the sauce in the fridge. Before serving, soften in a double boiler over warm water. Be careful: if the water is too hot, the sauce will curdle.