Classic Sauce Normande

A classic sauce Normande is based on fish velouté to which mushroom cooking liquid, mussel cooking liquid, and additional fish stock are added, giving the sauce deeper flavor and more complex character. The sauce is finished with heavy cream (in the manner of Sauce Suprême), lemon juice, and egg yolks (in the manner of Sauce Allemande). Classic recipes call for reducing the sauce after the addition of the egg yo