Place saffron threads into boiling water, set aside to steep.
Melt the vegetable shortening in a large pot over medium-high heat. Stir in the onions, and cook until golden, about 5 minutes. Season with cinnamon sticks, cloves, ginger, cumin, garlic powder, and cardamom seeds. Cook for 3 to 4 minutes to release the flavor, stirring constantly.
Pour in the rice and cook for 10 minutes, stirring constantly. Add the yogurt, saffron water, and salt. Bring to a simmer, then reduce heat to low. Cover pot with a cloth folded into 4 layers. Place a lid over the cloth and cook until the rice is done, about 20 minutes. Remove the cinnamon sticks, cloves, and cardamom seeds before serving.
