Beef Richelieu with Madeira Sauce Recipe

4 pounds beef tenderloin roast
1 tablespoon vegetable oil
1 cup beef broth
1/4 cup madeira wine
1/4 cup butter
2 tablespoons mushrooms, chopped
2 1/2 teaspoons arrowroot flour (found
in spice section)
a couple of dashes salt and freshly ground pepper.

Brown fillet in oil in large skillet over high heat. Transfer to shallow roasting pan and bake 25 minutes at 375 degrees for about 25 minutes for rare.

For sauce: combine broth, madeira, butter and chopped mushrooms and bring to a boil. Reduce heat and simmer 3 minutes. Mix some of the sauce with the arrowroot and then stir into pan. Continue simmering and stirring consistently until the sauce is similiar to heavy whipping cream, about 20 to 25 minutes. Season with salt and freshly cracked pepper.