Cut the vegetables such as onion, carrot, celery, and cabbage into bite-sized pieces.
Heat olive oil in a pot and sauté the onions first.
Add the rest of the vegetables like carrot, celery, cabbage, and bell pepper, and stir-fry.
Add minced garlic for flavor.
Pour in water or vegetable stock and bring to a boil.
Add tomatoes or tomato paste.
Season with salt and pepper to taste.
Simmer over low heat for 20-30 minutes until the vegetables are tender.