Preheat oven to 425 degrees F. Combine all ingredients except the pork and stir to blend. Place the roast in a roasting pan; rub with garlic mustard mixture until well covered. Place roast in preheated oven. Roast for 20 minutes.
Reduce heat to 325 degrees. Continue roasting meat until the internal temperature of the meat reaches 160 degrees F. Remove from oven, and allow to rest for 10 minutes before slicing.