In a small bowl, combine saffron with hot water and set aside to steep.
In a large bowl, combine rice with lukewarm water to cover; agitate it briskly with your hand, then pour off the water. Repeat 4 more times, or until the water is clear.
In a heavy 3-quart saucepan with a lid, bring 2 quarts water and salt to a boil. Add the drained rice, stir once, and return to the boil. Cook for 6 minutes. Transfer rice to a colander and rinse under warm water; let drain thoroughly. Wash and dry the saucepan.
In a small bowl, combine 1/2 cup of the cooked rice with the yogurt and half of the saffron water. In another bowl, combine the remaining rice with the pistachios. Add the cinnamon and cayenne to the remaining saffron water and mix into the rice-pistachio mixture until thoroughly combined.
In the saucepan, melt butter over medium-high heat. Remove from the heat and add the rice-yogurt mixture, spreading it into an even layer. Gently spoon the remaining rice mixture on top, pressing it into an even layer. Return the pan to medium-low heat. Cook uncovered for 5 minutes.
Cover the pan with a damp tea towel, or a double layer of damp paper towels, and the lid, folding the ends of the towel up and over the lid. Reduce the heat to very low and cook for 30 minutes, until a crust has formed on the bottom. Check the rice occasionally to be sure the bottom is not beginning to scorch (you will smell it if it is). Set the pan on a wet towel for 5 minutes to help loosen the bottom crust.
To serve, invert the whole dish onto a serving plate; if the crust sticks, which it is likely to, lift it up in pieces and set them upside down on top of the rice.
Yield: 6 servings
Related Recipe Categories
Vegetables and Sides