Place the rice in a large container and fill it with water. Stir the rice around for 2 minutes. Strain the rice and repeat the process 2 to 3 more times or until the water is almost clear.
Transfer the rinsed rice back to the container and add the salt. Cover it with warm water until the rice is submerged in 3" of water. Place a clean kitchen towel on top and let it rest for 4 hours.
Fill a large pot with water and bring it to a boil over medium-high heat. Drain the rice. Add it to the pot and let it boil for 3 minutes. Strain the rice and rinse it. Set it aside.
Grind the saffron threads to make a fine powder. Place it in a small bowl and add a tablespoon of cold water. Stir well and let it rest for 10 minutes. Stir again and let it rest for 5 more minutes.
In a separate medium-sized bowl, whisk the yogurt, ground turmeric, saffron mixture, and yolk until well combined. Add a quarter of the rice and use a wooden spoon to gently fold it into the mixture. The rice should be evenly coated.
Add the oil to a 4 or 5-quart saute pan set over medium heat. Add the yogurt-rice mixture and use a wooden spoon to spread it out evenly across the bottom of the pan. Let it cook for 5 minutes.
Add the remaining rice on top and spread it out evenly. Drizzle the ghee over the rice. Use the back of a spoon to poke holes in the rice without reaching the bottom of the pot but getting as close to it as possible.
Use a clean kitchen towel to wrap the pot's lid and tie it in place at the top (where the handle is). Reduce the heat to medium-low and cover the pot with the lid. Let the rice cook for 30 minutes or until the rice at the bottom is crispy.
Remove the pot from the heat and remove the lid immediately. Let it rest for 5 to 10 minutes. Slide the wooden spoon along the edges of the rice to help loosen it.
Place a large, extended plate over the pot. Wear an oven mitt or place a dry kitchen towel in the hand that will handle the pot. While pressing the plate down with one hand, secure the pot with your other hand. Carefully flip the pot and plate over. The tahdig should fall onto the plate.
Set it on the table and remove the pot. Enjoy with your favorite sides and mains.