Crush 1 1/2 teaspoons peppercorns, using a meat mallet or rolling pin. Coat a small heavy saucepan with cooking spray; place over medium heat until hot. Add crushed peppercorns, and cook 1 minute. Add Cognac; heat just until warm. Ignite with a long match; let flames die down. Add beef broth; cook over high heat 5 minutes or until reduced by half. Set aside.
Wrap handle of a small nonstick skillet with aluminum foil. Coat skillet with cooking spray; place over medium-high heat until hot. Add steak, and cook 2 minutes on each side. Immediately place skillet in oven. Bake at 400° for 5 minutes. Turn steak, and cook an additional 5 minutes or to desired degree of doneness. Remove skillet from oven. Place steak on a serving plate, and keep warm, reserving drippings in skillet.
Add reduced broth mixture, water, and remaining 1/2 teaspoon peppercorns to drippings in skillet. Place over medium-high heat; bring to a boil, stirring constantly. Slice meat into 1/4-inch-thick slices. Spoon broth mixture over meat, and serve immediately.