Combine the balsamic vinegar, garlic, cranberry sauce, brown sugar, red pepper flakes, salt, and olive oil in a large, re-sealable food storage bag. Reserve.

Pierce the roast all over with a knife and place it in the bag. Close the bag and massage the roast with the marinade. Refrigerate overnight, turning the bag occasionally.

Preheat oven to 350F degrees.

Remove the roast from the marinade and wipe it with a paper towel to remove excess marinade.

Heat the vegetable oil in a large cast iron pan over medium heat. Place beef in hot pan and sear until deep golden brown on all sides.

Add the marinade to the pan along with ½ cup beef broth and mix to combine. Add the cranberries and thyme and transfer the pan into the oven.

Roast for about 20 min per pound of meat OR until a thermometer reads 140F degrees for medium rare.

Remove from the oven and let rest for 15 minutes before carving and serving with the pan sauce.