bearnaise

noun

1. (sometimes lowercase) a sauce of egg yolks, shallots, tarragon, butter, vinegar, and sometimes white wine and chopped chervil.

noun

1. a rich sauce made from egg yolks, lemon juice or wine vinegar, butter, shallots, herbs, and seasoning

n.

“egg-and-butter sauce,” 1877, from French sauce béarnaise, from fem. of béarnais “of Béarn,” region in southwest France (named for the Benarni, a Gaulish tribe).