The key ingredient for authentic risotto is Arborio rice. Arborio's characteristics and cooking properties allow it to absorb the flavors and to retain a certain firmness through the unique "risotto" cooking procedure. The texture and cooking properties of imported Arborio rice coupled with saffron, the world's most expensive spice and is the classic risotto dish of Milan. This robust, intensely flavored dish is the most highly regarded of all risottos and is usually served with meats cooked in a red or wine sauce like Osso Buco.