Crumble one-fourth of ground beef into bottom of slow cooker. Top with one-fourth of tortilla wedges. In small bowl, combine soup and taco mix. Spread one-fourth of soup mixture over tortillas in pot. Sprinkle with one-fourth of tomatoes. Repeat layering until all ingredients are in pot. Cover and cook on LOW 4-5 hours. Spoon onto indiviual plates. Top each serving with sour cream, shredded lettuce, green onions, bell pepper and avocado.