Preheat oven to 375°F. Place Dutch oven on medium heat and add bacon. Cook for 10 minutes.
Add onions and cabbage and cook 5 more minutes.
Add cider and cider vinegar and bring to simmer. Cover and place in oven for 1½ hours or until cabbage is tender.
Place coarse ground pepper on plate. Season filets on all sides with kosher salt and press one side of filet firmly onto pepper until well coated.
Preheat cast-iron pan, add ghee and sear filet, pepper side first for 2 minutes. Sear all remaining sides, 2 minutes per side and place in oven to finish cooking. Remove when thermometer inserted into thickest part reads 125°F. Let rest 8 minutes before serving.
Slice filet and serve over bacon braised cabbage. Enjoy!