Saffron, once the most sought after trading good in the Americas, remains an expensive spice even today. Just a small pinch imparts incredible color and flavor found in few other spices.
1) Heat broth in a large pot over high heat; bring to a simmer. Cover and keep warm over low.
2) Melt butter and oil in a large saucepan over medium heat; add rice and cook 2 minutes, stirring. Add saffron and cook 1 minute, stirring.
3) Add reserved broth, one cup at a time, stirring until the rice has absorbed all the liquid before adding the next cup, until all broth is used. The process should take about 20 minutes.
4) When liquid is absorbed and rice is soft, remove from heat. Stir in cheese, season to taste with salt and pepper, and serve warm.