'set the yolks of four eggs in a pan over the fire until they are of the consistency of a custard, and then blend carefully with half a pint of melted butter. Great care must be taken that this does not boil, or it will be utterly spoilt. Add two tablespoonfuls of lemon-juice and a little chopped parsley, pepper, and salt and just a suspicion of nutmeg before serving.

This sauce is suitable for fish or cutlets, but it is too rich to suit every palate.