Remove roast from packaging and pat dry with a paper towel. Place in a casserole dish or baking dish.

Mix marinade together in a bowl by combining balsamic vinegar, olive oil, Worcestershire Sauce, brown sugar, minced garlic, smoked paprika, dried thyme, onion flakes, salt, pepper, dry mustard and red pepper flakes.

Pour over roast and turn to coat both sides.

Use a tenderizer or sharp knife to get the marinade down into the meat on both sides.

Cover and refrigerate 4 -8 hours.

Remove from refrigerator and allow to come to room temperature about an hour before cooking.

Prepare a grill fire to about 350° with oak or hickory for smoke flavor.

Place roast on the grill and pour remaining marinade over roast. Cook roast over indirect fire for 1 hour with the grill closed.

Check internal temperature with a digital thermometer and cook until desired doneness. We cooked ours to about 150° for medium.

Remove from grill and allow to rest 15 minutes before slicing thin for serving.