1Spray 5- to 6-quart slow cooker with cooking spray. In large bowl, mix chili powder, salt, garlic powder and cumin. Add potatoes, sweet potatoes and onion to bowl; stir to coat. Place vegetables in slow cooker.
2Remove netting from pork. Rub oil over pork; roll in spices in bowl to cover. Place pork over vegetables. Pour tomato sauce, tomatoes and chopped chile over pork and vegetables.
3Cover; cook on Low heat setting 6 to 8 hours.
4Remove pork and vegetables from cooker; cover to keep warm. Pour sauce from cooker into 3-quart saucepan. In small bowl, mix water and cornstarch; stir into sauce. Cook over high heat 5 to 10 minutes, stirring frequently, until thickened. Serve sauce with pork and vegetables.