Cut onions, celery, carrots, tomatoes, and other vegetables into bite-sized pieces.
Heat olive oil in a large pot and sauté onions, celery, and carrots.
Once the vegetables are slightly cooked, add tomatoes, cabbage, and bell peppers.
Add water, salt, and pepper, and bring to a boil over high heat.
When it starts boiling, reduce to medium-low heat and simmer for 20–30 minutes.
Add herbs or chili powder to taste.
When the vegetables are fully cooked, turn off the heat and serve in bowls.