Combine first 3 ingredients in a large zip-top plastic bag. Trim fat from steak. Score a diamond pattern on both sides of steak. Sprinkle the peppercorns over both sides of steak, pressing pepper into steak. Add steak to bag; seal and marinate in refrigerator 1 hour. Remove steak from bag; discard marinade.
Place steak on grill rack coated with cooking spray; grill 4 minutes on each side or until desired degree of doneness. Cut steak diagonally across the grain into thin slices.