- Combine wine, shallots and tarragon. Cook over low heat until the wine is reduced and you have a glaze-like mixture.
- In a blender, mix egg yolks and salt.
- Slowly pour the wine mixture into the blender, blending as it is poured.
- Heat the butter in a saucepan until it bubbles, but don't let it brown or burn! Slowly pour the melted butter into the blender and blend just a bit until the sauce gets to a thicker consistency.