Demi-glace: Preheat the oven to 200 °C. Wash the bones well, let them drain, and roast them for a few minutes in the oven in a large pot to melt the fat, making it easy to remove.
Meanwhile, clean the onions, carrots, and celery, wash them, and cut them into large chunks. Remove the bones from the oven and place them together with the oil and meat scraps in a large pot. Sauté everything over high heat until well browned. Add the vegetable chunks and garlic and let them brown as well. If there is too much fat in the pot, skim it off.
Add the red wine to deglaze the ingredients and scrape all the browned bits from the bottom of the pot. Stir in the tomato paste. Then add the water and all the herbs. Let it simmer for 5-6 hours on low heat. Allow the sauce to cool after cooking. Strain the mixture using a cheesecloth and a fine sieve to obtain a clear demi-glace.
Vegetable broth: Sauté the chopped onion, celeriac, carrot, celery, and tomato in a pot. Add about 2 liters of water and bring to a boil.
Cooking the risotto: Sauté the rice for 1.5 minutes in a pot with some butter, oil, salt, and pepper until the rice becomes translucent. Ensure the heat is low enough to prevent burning. Add the onion and deglaze with white wine or, for a luxurious version like Filippo does, with Don Perignon. Gradually add the broth and cook until the rice is done. Season with salt, if necessary. Remove the pot from the heat and cover with a lid. Let the risotto rest for 1 minute.
Mantecatura: Now add the butter, Parmesan cheese, and scamorza. Mix everything well into the risotto until it is creamy and well combined.
Serving: Spoon the risotto onto deep plates, garnish with a spoonful of demi-glace, and grate fresh truffle over it to taste.
