Preparation - In a small bowl, mix the French dressing, onion, brown sugar, Worcestershire sauce, chili powder and garlic together; set aside. Place the pork in a roasting pan. Roast in a preheated oven at 375º for 45 minutes. Brush with half of the sauce mixture, then continue roasting for an additional 45 minutes to 1 hour, basting one or two more times with the remaining sauce. Shred the pork into bite size pieces. Serve on sandwich rolls.