Hollandaise sauce, one of the crowning glories of French cuisine, is reputedly tricky to make, for it uses egg yolks that may curdle if heated too fast. With this recipe, the sauce may be prepared in advance and, according to my mother, cannot fail. You can make it up to a day ahead of time, refrigerate and reheat gently when ready to serve. The best approach, however, is to make the sauce just before serving.
Hollandaise sauce is traditionally served over asparagus or poached fish. It also adds a touch of elegance to dishes like eggs benedict. This recipe will make about a cup of sauce.
3 egg yolks
juice of 1/2 lemon (at room temperature)
1/4 tsp. salt
4 oz. (125 g.) unsalted butter (1 stick)
2 tsp. boiling water
freshly ground black pepper
In a small mixing bowl, whisk the egg yolks until well-blended.
Squeeze the half lemon through a sieve into a small cup. Add 1/2 tsp. of this juice to the yolks. Add the salt. Whisk again.
Melt the butter in a small saucepan. In a second small saucepan, heat a small quantity of water to boiling. Keep it over the heat at a simmer.
Begin adding the melted butter to the yolks, teaspoonful by teaspoonful, whisking constantly. When the sauce begins to thicken, add a few more drops of lemon juice.
Continue in this way until all the butter and juice have been incorporated. Stir in 2 tsp. of the boiling water.
Grind in some pepper and check the flavorings, adding more salt if 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, heat an inch (5 cm) of water to lukewarm in a large pot. Turn off the heat. Place the bowl of sauce in the pot, taking care not to get any water into the bowl, and stir the sauce occasionally until it has softened. Be careful: if the water is too hot, the sauce will curdle.
Note: If your sauce refuses to thicken, there is an easy remedy. Spoon a little boiling water (1 tsp.) into a clean bowl. Add 1 tbsp. of the sauce. Stir to blend. Keep adding the sauce little by little until it thickens. Then gradually stir in any remaining melted butter.