Place 1 ½ cups dried Basmati rice in a large bowl and cover with water. Allow to soak for up to 3 hours, but at a minimum 30 minutes. Then pour off the water.
Salt a large pot of water and bring it to a boil. Once boiling, add 1 cup peeled fava beans. Cook for 2 minutes.
Add the soaked rice into the pot along with 2 tbsp of dried dill. Reduce the heat to a simmer. Cook for about 7-10 minutes, or until the rice is almost cooked all the way.
Remove about ½ cup of the cooked rice and rinse. Add 3 tbsp of saffron water into the reserved rice and mix to fully combine.
Add the remaining dill into the unreserved rice still in the pot and stir to combine.
Peel three potatoes and cut them into thick slices.
Add a thin layer of oil into the bottom of your large pot. Add the sliced potatoes as the bottom layer, then add the reserved saffron rice as the next layer. Add the remaining dill rice.
Use the back of a spoon to poke holes in the rice, then drizzle ¼ cup of water over the top. You can also sprinkle with another 1-2 tbsp of the saffron oil and add the ½ tsp cinnamon (optional) if desired.
Wrap the lid in a kitchen towel and place firmly on top of the pot. Allow to cook on low heat for another 40 minutes
When done, flip the contents of the pot onto a serving platter. Melt 4 tbsp butter and pour over the rice. Enjoy!