Wash onion, celery, carrot, and cabbage thoroughly and dice them.
Heat olive oil in a pot and sauté the onion.
Add celery, carrot, and cabbage and stir-fry for another 2–3 minutes.
Add diced tomatoes and water, then bring to a boil.
Season with salt, pepper, herbs, etc.
Simmer on low heat until all ingredients are well cooked.