1. Prepare béarnaise sauce mix according to package directions, stirring in lemon juice and chopped fresh tarragon during last minute of cook time.
Note: For testing purposes only, we used McCormick Béarnaise Sauce Mix. Speedy Béarnaise Sauce can be made 1 day ahead and stored in the refrigerator. To reheat, place bowl over simmering water, and cook, whisking constantly, until mixture is warm.