Chop an onion for the risotto, sauté in a saucepan with a little butter until translucent, add the long-grain rice and heat over low heat, stirring with a wooden spoon. Add a little vegetable soup, continue stirring, add clear soup repeatedly, continue stirring and so on until the long-grain rice has reached a consistency that is still quite firm to the bite.
For the involtini, finely chop the chanterelles and the other onion, sauté in a frying pan and continue cooking over low heat with truffle oil, then cool.
Cut the meat into eight narrow slices, carefully flatten them, season with salt and season with pepper. On each slice, place a small amount of the chanterelle and onion mixture, top with small slices of summer truffle and cover with Castelmagno cheese cut into small slices about 4 cm long.
Form the meat slices into rolls and pierce each with a wooden stick. Brown the involtini on both sides in a coated frying pan with a little bit of butter, extinguish with the wine, add the remaining butter and continue to simmer on low heat. Add Parmesan cheese, the rest of the clear soup and saffron to the risotto and cook until done, stirring continuously.