Very roughly crush peppercorns. An easy way is to place them between two heavy cutting boards and press down with a rolling motion. They should be pressed flat, but pieces as big as 1/2 are OK.
Press beef into peppercorns, lightly covering each side.
Heat heavy skillet with oil and butter until well melted on medium high. Mix together. Place beef into skillet; make sure oil/butter coats it. Flip halfway through. Cook about 4 minutes/side for medium. This will, of course, depend on the thickness of the beef, its temperature, etc.
Remove beef to plates. Add cognac and quickly cover pan. It will splatter. When the splattering dies down, scrape up the brown bits until you have a thickish but light gravy, about 4 minutes. Add cream. Continue stirring and cooking, about 1 minute. Pour sauce over steaks.