In a large skillet, heat italian dressing. Add onion, bell pepper, and chicken. Mix well to combine, and cook over moderate heat for approximately 6 minutes, stirring occasionally.
In a small bowl, combine italian seasoning, sugar, and undrained stewed tomatoes. Spoon this over the chicken evenly, and lower heat so chicken is just simmering. Simmer for about 12-14 minutes, stirring occasionally. When chicken is fork-tender, it is ready to be served over hot noodles.