Heat a grill to medium. Put the steaks the grill and cook to desired doneness.
Bring the water to a boil in a medium pot over medium heat. Add the au jus mix and the brandy. Let boil for 10 minutes. While that cooks, in a separate small saucepan, combine the margarine and the flour to make the roux. Let the roux cook for 5 minutes. Add roux to the au jus mixture and stir with a wire whisk until smooth. Stir in the cream and the black pepper. Arrange the steaks on serving plates and serve drizzled with the sauce.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.