So there you have it: just make the risotto as you normally would, starting with a soffritto of onion sautéed in butter. Here you want only butter, and a lot of it, to underscore the sweetness that is characteristic of the dish.
Then add your baby yams, peeled and cut into small dice, and allow them to sauté gently to soak up the aromas of the seasoned butter (insaporire).
Then proceed in the usual manner, toasting your rice, then adding successively a splash of white wine, then ladlefuls of broth, letting each evaporate before adding the next.
At the end of cooking, add the grated parmesan and a dab of sweet (preferably cultured) butter and stir vigorously for about a minute off heat. The yams will have dissolved completely into the risotto, lending its sweet flavor, lovely golden color and a subtle, velvety texture to the rice.
Serve your risotto alla zucca immediately.