Béarnaise Sauce for Barbecue

Prepare the initial base by mixing egg yolks, white wine, and white wine vinegar in a stainless steel bowl.

Whisk the mixture over a double boiler until it becomes very airy and reaches a thick texture (Dutch consistency).

Slowly incorporate the clarified butter in a thin stream, whisking continuously, as if making mayonnaise.

For the reduction, mix the red onion, a little white wine (or white wine vinegar), pepper, and dried tarragon in a separate section. Heat over low heat.

Let the onion and seasoning mixture reduce over low heat until the volume has halved.

Mix the onion reduction into the base sauce (emulsified Béarnaise).

Finish by seasoning the Béarnaise sauce with lemon zest or juice, salt to taste, and more pepper.