A traditional sauce allemande is prepared by finishing a sauce velouté with egg yolks. Egg yolks can also be used to thicken reduced stocks for lighter-textured modern sauces. One method of using egg yolks as thickeners is discussed in Chapter 13, “Hot Emulsified Sauces”. The other method is given here. Remember that egg yolk–thickened sauces must never be allowed to boil unless they contain a large amount of flour.