In a large stockpot or Dutch oven heat 1 tablespoon of olive oil over medium high heat. Add the chopped yellow onion to the pot and saute for approximately 3-4 minutes, or until translucent and fragrant. Add the minced garlic to the onions and stir to combine. Cook the onions with the garlic for 1 minute before adding the chopped celery, carrots, bell pepper, cherry tomatoes, salt and pepper, dried parsley, dried Italian seasoning and crushed red pepper flakes. Mix well and cook for approximately 5 minutes or so.
Add the chicken or vegetable stock to the vegetables and increase heat to high. Cover the pot with a tight-fitting lid and bring the soup to a boil. Once boiling, reduce to a simmer. Continue to cook, covered, for approximately 30 minutes.
Remove cover and add the zucchini, green cabbage, chopped broccoli and green onions to the soup. Cook for an additional 20-30 minutes, or until vegetables reach desired doneness.
Garnish with fresh chopped parsley, green onions and red chili flakes (if desired).
*Other vegetables that would be delicious in this soup- turnips, sugar snap peas, artichokes.