Place steak in shallow dish. Rub with olive oil and sprinkle with salt and pepper. Let stand at room temperature 1 hour.

While steaks are standing, combine Port, red wine and vinegar in a skillet and reduce down until syrupy. Add chicken broth, continue cooking and reduce by half. Transfer to a bowl and set aside.

Heat skillet over medium-high heat. Add steaks and fry until cooked to desired doneness. Transfer steaks to a serving place; tent loosely with foil to keep warm.

Add wine reduction to skillet, stir, scraping all the browned bits from the pan into the sauce. Whisk in cheese until smooth. Pour over steaks and serve.

Yields about 1 cup.