Rinse the rice: Wash the rice several times until the water runs clear, then soak in cold water with a tablespoon of salt for 30 minutes. Drain.
Infuse the saffron: Crush the saffron threads and dissolve in 2 tablespoons of hot water. Set aside.
Parboil the rice: Bring a large pot of water to a boil. Add the rice and boil for 5–7 minutes until the grains are soft but still firm in the center. Drain the rice.
Prepare the pan: Melt 2 tablespoons of butter or oil in a non-stick pan over medium heat. Add a layer of rice to the bottom of the pan.
Layer the rice: Gently spoon the remaining rice over the first layer, forming a pyramid shape.
Steam the rice: Cover the pan with a lid wrapped in a kitchen towel to catch moisture. Cook over low heat for 30–40 minutes.
Add saffron: Pour the saffron mixture over the top layer of rice before serving.
Serve: Flip the rice out onto a plate to reveal the crispy, golden tahdig crust on the bottom.