In a medium saucepan, heat 20 gr of butter over medium-high heat, and add the onion diced, sautéing until it becomes soft and translucent.
Add the rice to the pan, and toast it, stirring constantly, for a couple of minutes. Add the white wine, and stir until it has evaporated and the rice is translucent.
Add one ladleful of broth, stirring until all of the liquid has been absorbed. And reapet adding one ladleful of the warm broth at a time, stirring constantly toensure even cooking.
When the rice is al dente, stir the saffron-infused broth into the risotto. Season with salt, to taste. Remove the pot from the heat, and add the remaining butter and Parmigiano Reggiano. Stir until the ingredients are completely incorporated. Serve the risotto and enjoy!