Plce the filets on a board and pat them dry with paper towels; sprinkle with salt and then press the black pepper evenly on both sides.
Allow to rest at room temperature for 15 minute.
Heat 1 1/2 tablespoons of the butter or margarine and the oil in large saute pan over med-high heat until it almost smokes. Place the steaks in pan and lower the heat to medium.
Saute steaks for 4 minutes on one side and then 3 minutes on other side, for medium rare. Remove to a serving platter and cover tightly with aluminum foil.
Meanwhile, pour all but 1 tablespoon of fat from the saute pan; add the shallots and cook over med heat for 2 minutes. Add the beef broth and cook over high heat for 4-6 minutes, until reduced by half, scraping the brown bits from the bottom of the pan.
Add the Cognac and cook for 2 more minutes. Off the heat, swirl in the remaining 2 tablespoons of butter and 1/2 teaspoon salt.
Serve the steaks hot with the sauce poured on top; sprinkle with parsley, if desired.
These would be wonderful with a side of mushrooms, a baked potato, asparagus, freshly baked bread and a lovely wine!