Spray 8-inch skillet with cooking spray. Add onion; cook over medium heat about 3 minutes, stirring occasionally until crisp-tender. In slow cooker, mix crumbles, onions, beans and enchilada sauce. In medium bowl, stir corn bread mix, milk, butter and egg just until moistened. Stir in cheese and chiles. Spoon over mixture in slow cooker. Cover; cook on Low heat setting 4 hours 30 minutes to 5 hours 30 minutes or until toothpick inserted in center of corn bread comes out clean. Serve tamale pie with sour cream and green onions.