For the three-floret risotto, chop the onion and sauté in a pot with the olive oil until translucent. Wash and add the rice and fry briefly. Drain with the vegetable soup and add the Brussels sprouts mixture.
Cover the risotto and simmer for about 20 minutes. Add a little water if necessary. Stir the Parmesan into the finished risotto and season with salt.
Serve and sprinkle the Three Sprouts Risotto with the remaining Parmesan.