Add beef and onions to 10-inch skillet, breaking beef into small pieces. Cook over medium-high heat 7 to 9 minutes, stirring frequently, until beef is brown; drain. Add beef mixture to slow cooker with carrot, bell peppers, tomatoes, tomato sauce, broth, seasoning and sugar; stir to combine. Cover; cook on High heat setting 2 to 2 1/2 hours or until vegetables are crisp-tender. Stir in rice; cover, and cook about 20 minutes longer or until soft.