2 tb Vegetable oil
1 1/2 c  Fish stock
Black pepper to taste
2 tb Worcestershire sauce
1/4 c  Parsley,chopped
2 tb Flour,all-purpose
Salt to taste
1/2 c  Butter,unsalted
1    Juice of lemon

1. Heat oil in heavy skillet; remove from heat and add flour.
2. Return to heat and cook, stirring, until roux is medium brown in color.
3. Slowly whisk in stock; bring to a boil, stirring constantly, and simmer
45 minutes.
4. Add salt and pepper.
5. Reansfer sauce (there should be about 1 cup) to 2-quart saucepan; bring
to a quick boil.
6. Whisk in softened butter and Worcestershire sauce; continue to whisk
until butter is absorbed.
7. Add lemon juice and parsley; whisk again briefly and remove from heat.
8. This sauce should be used within 45 minutes from time ir is completed.
NOTE: Recipe is time-consuming but results are well worth the effort.