Heat the olive oil in a large saucepan. Clean the vegetables, cut them into small pieces and add them. Fry a little, then deglaze with half a liter of stock and add the rice. Let the rice cook for about 20 minutes and gradually add the broth so that everything stays covered. Salt and pepper the vegetables. If necessary, season with other spices or herbs.
As soon as the rice is done, mix in the sour cream and let it boil briefly.
If necessary, sprinkle cheese (e.g. Parmesan) on top.