Pierce Rotisserie or Oven /Roast all over with fork. Place in large sealable freezer bag with Diana sauce original; refrigerate for 8-12 hours. Discard marinade after use. (If using Premium Rotisserie/oven roasts, marinate for 1-2 hours or simply rub all over with some of the sauce).
Place drip pan under grill; add 1/2 inch of water to pan. Preheat barbecue to medium-high (400F) . Cook using indirect heat or Rotisserie. Cook roast at constant heat in closed barbecue until thermometer reads 140F for medium-rare, about 20-25 minute per lb. Transfer to cutting board, cover with foil and let stand for up to 30 minutes. Serve warm, carving into thin slices or cover and refrigerate for up to 2 days.
INDIRECT HEAT: Place roast on grill over drip pan that is moved ot one side and filled with 1/2 inch of water ; turn off heat under just the roast. Insert meat thermometer into middle of roast. (If using a 3-burner barbecue, position roast and drip pan in center of barbecue, turn off center burner) ROTISSERIE: insert spit rod lengthwise through center of roast; secure with holding forks and place over drip pan. Insert meat thermometer into middle of roast avoiding spit rod.
CHUNKY CHOW-CHOW RELISH:
Cook cauliflower florets and carrots in pot of boiling salted water until tender, about 4 minutes. Drain well; place in bowl. Stir in green peppers, chopped red onions, Diana sauce, vinegar, minced fresh parsley and hot mustard. Cover and refrigerate for up to 1 week. Makes 4 cups.