Chervil-Butter Sauce for Fish

• 2 teaspoons flour
• Salt and freshly ground pepper, preferably white, to taste
• 4 tablespoons (1/2 stick) butter, cut into 4 or 5 pieces
• 1/2 cup finely minced fresh chervil leaves
• 1 teaspoon fresh lemon juice
• 1 tablespoon minced shallots
• 2 teaspoons minced fresh tarragon leaves or 1/2 teaspoon dried
• Salt and freshly ground black pepper to taste
• 3 tablespoons white wine or other vinegar
• 2 egg yolks
• 8 tablespoons (1 stick) butter, cut into pieces
• Fresh lemon juice if necessary

1. In a small saucepan, whisk the flour with 1/2 cup water; season with salt and pepper.
2. Set it over low heat and cook, stirring.
3. Add the butter one piece at a time, stirring until each bit melts before adding the next one.
4. Keep the heat low, stir frequently, and do not let the mixture boil.
5. When all the butter has been incorporated, the sauce should be smooth and thick.
6. Taste for salt and pepper, stir in the chervil and the lemon juice, and serve immediately.
7. In a small saucepan, heat together the shallot, most of the tarragon, the salt, pepper, and vinegar, until most of the vinegar has evaporated, about 5 minutes.
8. Cool.
9. Beat the egg yolks with 1 tablespoon water and stir into the vinegar mixture.
10. Return to the stove over low heat and beat continuously with a wire whisk until thick.
11. With the heat as low as possible, use a wooden spoon to stir in the butter a bit at a time.
12. Add the remaining tarragon and taste; add salt and pepper if necessary and, if the taste is not quite sharp enough, a bit of lemon juice.
13. Use immediately.

flour, salt, butter, chervil, lemon juice, shallots, tarragon, salt, white wine, egg yolks, butter, lemon juice

Taken from www.epicurious.com/recipes/food/views/chervil-butter-sauce-for-fish-385944 (may not work)