Place steak into a large resealable bag or shallow dish. Pour in the dry vermouth and sweet vermouth and stir to coat the steak. Seal or cover and refrigerate for 6 hours to marinate.
STEP - 3
STEP - 4
Heat the oil in a large skillet over medium heat. Remove steak from the bag and discard the marinade. Season the steak on both sides with red pepper flakes. Fry for 3 to 4 minutes per side for medium-rare, or to your desired degree of doneness. Let rest for a few minutes before serving.