Heat oil in a large pot over medium heat. Add onions, carrots, and celery. Cook, stirring until the vegetables begin to soften 6 to 8 minutes. Add bell pepper, garlic, Italian Seasoning, pepper, and salt and cook, stirring for 2 minutes.
Add broth, cabbage, and tomato; increase heat to medium-high, and bring to a boil. Reduce heat to maintain a simmer, partially cover and cook until all vegetables are tender, 15 to 20 minutes more.