Peel the onion and cut into fine rings.
Mix the rice with salt, pepper, bay leaf and onion.
Add the wine and steam in the steamer at 100 °C for 4 minutes.
Pour half of the vegetable stock and steam for another 8 minutes at 100 °C.
Pour the rest of the vegetable stock as well. Now steam for another 10 minutes.
Cut the pumpkin into cubes and steam at the same time.
Finely puree 200 g of the pumpkin, leave the rest in cubes. Mix the pumpkin and pumpkin cubes into the risotto and finish with Parmesan cheese and butter.