Sprinkle the meat with salt and pepper to taste. Heat the oil in a large skillet, large enough to hold the slices in one layer. Brown the meat on both sides, about 1-2 min. to a side. Or cook longer if you prefer meat well done.
Transfer the meat to a heated serving platter and keep warm.
Pour off the fat from the skillet. Add 1 tablespoon of the butter and when it is hot, add the shallots. Cook briefly, stirring, then add the wine. Cook until almost reduced by half. Stir in the brownsauce and cook about 2 min.
Put the sauce through a fine strainer into a small saucepan. Add salt and pepper to taste. Swril in the remaining butter. Spoon the sauce over the meat and garnish with watercress.