Mornay: Béchamel combined with Gruyère cheese and egg yolks.
Crème: Béchamel with heavy cream and lemon juice.
Soubise: Onions sweated in butter and added to Béchamel.
Smitane: Classically but no longer made from Béchamel. Chopped onions sweated in butter, moistened with white wine and reduced; sour cream added.