Finely chop the onion and sauté with the carrots. Sprinkle sugar on top, 1 tablespoon or a little more as you like and then sweat tomato paste. Cut the cabbage into large cubes, wash and place on top. Simmer a little while stirring constantly. Add the diced tomatoes and 1/2 liter of vegetable stock. Let simmer gently. The herb must be soft, but not crumble.
As a vegetable, the tomato sauce should stay thick. Add a little more stock as soup and season to taste.