Place first 4 ingredients in a large greased roaster or foil pan.
Melt butter in small saucepan on low. Stir in remaining 8 ingredients.
Drizzle over vegetable mixture. Toss until well coated. Cover with lid or foil. Preheat gas barbecue. Place roaster on grill & reduce burner to medium-low. Close lid of barbecue and cook about 30 to 45 minutes, shaking roaster occasionally, until heated through.