1Mix refried beans, black beans, corn, salsa, chilies, adobo sauce and 1 cup of the cheese in 1 1/2- to 2-quart slow cooker.
2Cover and cook on Low heat setting 3 to 4 hours, stirring after 2 hours.
3Sprinkle with remaining 1/2 cup cheese and the onions. Serve with tortilla chips. Dip will hold on Low heat setting up to 2 hours; stir occasionally.