Finely chop onion and sauté it in a pot with a little EVO oil. Add rice and toast it on medium heat.
Add dry white wine, allow it to evaporate and cover with hot stock.
Add part of the blended pumpkin and cook, gradually alternating more stock, as it evaporates, and pumpkin. Stir frequently until rice is fully cooked.
Remove from the heat, add butter and quickly mix. Allow to rest for 2 minutes. Thin Parmigiano Reggiano and white truffle spread down with a little hot stock until you get a smooth creamy sauce.
Serve the still hot risotto topped with the Parmigiano Reggiano and white truffle creamy sauce. Garnish with slices of black truffles and fresh rosemary to taste.