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 minutes, or until the rice has slightly softened. Add the noodles, stir and remove from the heat.
Drain the rice and noodles in a colander, rinse and set aside.
Spread four tablespoons of oil in a nonstick pot.
In a small bowl, mix 1 cup of the lightly cooked rice-noodle mixture with 2 tablespoons of saffron-water mixture, gently mix and spread evenly in the bottom of the pot. This will be the crispy rice referred to as Tahdig.
* Alternatively, you can place a piece of lavash flat bread on the bottom of the pot for a bread Tahdig.
Begin by layering a 1/3 of the partially cooked rice-noodle mixture and a 1/3 of onion mixture into the pot and repeat until all of the rice and onion mixture have been layered in the pot.
Wrap the lid with a clean towel and place it on the pot. Allow the rice to steam over medium-low heat for about 45 minutes.
Add the remaining saffron water to the rice and gently fluff using two forks.