Combine vinegar, soy sauce, brown sugar, 1 teaspoon salt and remaining spices in a mixing bowl. Whisk until sugar and salt dissolve.
Pour marinade into a heavy-duty zipper-locking bag and marinate for 24 hours, rotating roast in marinade at least once.
Preheat oven to 450°F. Remove roast from marinade, discard remaining marinade and pat dry. Place in a roasting pan or on a wire rack in a sheet pan. Roast for 15 minutes; reduce heat to 325°F and roast for about 1 hour and 15 minutes or until the roast reaches an internal temperature of 125°F for a deep pink interior.
Allow roast to rest for at least 15 minutes before slicing thinly.