Melt the butter in a saucepan over very high heat. Add the rice and stir continuously until the rice is very hot but not browned. Add the vanilla bean, rum, and water; cook until almost all the liquid has evaporated.
Add a small amount of the milk and stir until it has been absorbed by the rice. Continue to add the milk in small amounts until it has all been absorbed and the rice is cooked. This process will take 15 - 18 minutes in total.
Remove the pan from the heat and add the cream, sugar, orange and lemon zest, and chocolate. Stir well to incorporate all the ingredients. Serve at once.
Reprinted with permission from ©Massimo Capra, Massimo's Italian Kitchen: Authentic One-Dish Meals from a Seasoned Chef, published by Sellers Publishing click for book review