 In fact, the earliest known French recipes of the sauce appear to be recipes for an aspic, not a sauce; Viard's 1806 recipe for "poulets en mayonnaise" describes a sauce involving a velouté, gelatin, vinegar, and an optional egg to thicken it, which gels like an aspic.The word "mayonnaise" is attested in English in 1815.The origin of the name is unclear.