In a large resealable plastic bag, combine flour, salt if desired and pepper. Add steak and shake to coat. In a large skillet, brown beef on both sides in oil over medium heat until no longer pink.; drain. Add the tomatoes, onion and chilies; bring to a boil. Reduce heat; cover and simmer for 30 minutes.
Add potatoes and carrots. Cover and simmer for 70-80 minutes or until meat and vegetables are tender. Combine cornstarch and water until smooth; stir into skillet. bring to a boil, cook and stir for 2 minutes or until thickened.