Clean the carrots and brown mushrooms. Peel the onion. Chop the vegetables roughly.

Heat the vegetable oil in a large pan on high heat. Fry the vegetable chunks a couple of minutes. Stir them from time to time. When they are browned from all sides, add tomato purée and keep on frying while stirring constantly.

Lower the the temperature to medium heat and deglaze with balsamic vinegar and soya sauce. Add vegetable broth and let it all cook for about 30 minutes. Stir every now and then. If the sauce thickens too much, just add a little bit of water. Is the sauce still too thin, just raise the temperature and let it thicken down a bit. Just before serving, pour through a sieve. You can reuse the vegetables later oder just serve them directly as a side dish.