In a large covered pot, bring 8 cups of water and salt to a boil.
Add the rinsed rice and boil on high heat uncovered for about 5-7 minutes, or until the rice has slightly softened.
Turn the heat off, remove and strain about one cup of the boiled rice and place in a small bowl. Combine with 1 tablespoon of the saffron-water mixture and gently mix. Set aside.
Add the dill and fresh fava bean to the big pot with the remainder of the rice and gently stir.
Drain the rice mixture in a colander and set aside while you prepare the pan.
Melt 2 tablespoons of ghee in the same pot over low heat.
Spread the saffron rice evenly in the bottom of the pot. This will be the crispy rice referred to as the Tahdig.
Pour the remainder of the rinsed rice, fava bean and dill mixture to the pot and lightly fluff with a fork.
Cut up the remaining 2 tablespoons of ghee into pieces and evenly spread over the top of the rice.
Pour 1/4 cup of water evenly over the top of the rice. Wrap the lid with a clean towel and place on top of the pot. This will allow the rice to steam.
Steam the rice over a medium-low to medium heat for about 45-50 minutes.
Pour the remaining 1 tablespoon saffron water over the top of the rice. Turn off the heat and allow to cool for 5 minutes before serving.
When serving this dish to guests, I typically use a non-stick pot so that I can flip the rice over and serve it upside down showcasing the crunchy saffron tahdig.