Peel and finely slice onions and garlic. Peel and grate carrot. Roughly dice bacon. Wash radicchio, dry and slice roughly.
In a pot, heat some olive oil, then add yellow onions and carrots. Fry until the onions turn golden brown, then add rice and stir in well. Pour over the vegetable stock, give it a stir, and let it cook for about 10-15 minutes, stirring occasionally. At this point, add a little water as needed and keep stirring occasionally, until the rice is cooked through. Give it a taste and add salt as needed.
While the rice is cooking, heat a grill pan and add some olive oil. Then, add finely sliced red onion, sliced or diced garlic and diced bacon. Fry until the onions tenderize and the bacon fries up, then add sliced radicchio and mix in well. Season to taste with salt and pepper, then let it cook for a couple of minutes, until the radicchio wilts down. Remove from heat and set aside.
Place cooked rice on a plate a top with the cooked radicchio, pouring over any leftover juices from the pan. Top with grated parmesan and serve.