Creamy Tarragon Sauce

1/4 cup butter or margarine
1 Tablespoon all-purpose flour
1 cup milk
1/2 cup sour cream
1 teaspoon dried tarragon
1 teaspoon dried chervil
1 teaspoon dried basil
1 teaspoon garlic powder
1/2 teaspoon salt
1/2 teaspoon ground black pepper

Melt butter in a medium saucepan over medium heat; stir in flour. Cook 1 to 2 minutes or until flour is brown. Gradually add milk; stir until flour mixture dissolves. Continue to cook, stirring constantly, until sauce thickens. Stir in sour cream, tarragon, chervil, basil, garlic powder, salt, and pepper. Store in an airtight container in refrigerator.