Bearnaise sauce, a hot emulsion similar to hollandaise, features clarified butter, egg yolks, a little vinegar, and a touch of the flavor of tarragon. Typically used as a protein finish.
To clarify butter: melt it over low heat without stirring. Once it has melted, remove from heat and skim off the solids floating on top.
1/4 cup white-wine vinegar
1 small shallot, minced
½ Tsp pepper
1 Tbs plus 1 teaspoon chopped tarragon leaves
2 egg yolks
12 Tsp unsalted butter, melted
Salt, to taste
Dash of lemon juice
If the flavor is not tangy enough, add a splash of lemon juice. If the sauce is too thick, stir in a little hot water. Add the remaining tarragon leaves, and serve.