Lightly season the filets with salt and pound cracked pepper into both sides.
Heat the butter in a sauté pan over high heat. Add the filets and brown on both sides (rare 10 minutes; medium-rare 15 minutes, medium 18 minutes, medium well 20 minutes, well done 25 minutes.
Remove from pan and keep warm. Deglaze the pan with the brandy, add the cream and reduce to a semi-thick consistency over medium heat, approximately 1 1/2 minutes Add the demi-glace and cook about 1 minute more. Taste for seasoning and adjust if necessary. Center each filet on a hot dinner plate, ladle sauce over. Garnish with watercress.
Makes: 6