Saute onions, green bell peppers, and garlic in a small amount of vegetable oil. Add chicken, taco seasoning mix, salsa, vegetables, beans, tomato paste, and chicken broth. Adjust liquid to your liking. Bring to a slow simmer and simmer for 20 minutes. Place cream cheese in a separate bowl. Using a measuring cup, take some of the hot liquid from the soup and pour over cream cheese to melt and then add back to the soup. Simmer on low for another 10 minutes. Serve with tortilla chips and grated Monterey jack cheese.