01 -
In a big resealable food bag, stir together balsamic vinegar, garlic, cranberry sauce, sugar, pepper flakes, salt, and olive oil. Save it for later.
02 -
Poke the roast with a knife all over, toss it in the bag, seal it, and squish the marinade around to coat the meat. Chill overnight, flipping now and then.
03 -
Heat the oven to 350°F. Take the roast out and pat it dry with paper towels to get rid of the extra marinade.
04 -
Pour vegetable oil into a hot cast iron skillet on medium heat. Cook the roast in the pan until all sides are browned nicely.
05 -
Pour the marinade and beef stock into the pan. Toss in the cranberries and thyme. Pop the pan in the oven to cook.
06 -
Roast for 20 minutes per pound of meat or until the inside hits 140°F for medium rare.
07 -
Pull it out of the oven, set it aside for 15 minutes, then slice it up and serve with the sauce from the pan.