Place basmati rice into a bowl. Wash several times until the water becomes clear and less cloudy completely.

Cover rice with water and salt. Let it soak for at least one hour before cooking for fluffy texture.

Fill a large pot with water. Bring the water to a rolling boil over high heat carefully.

Drain soaked rice and add into boiling water. Cook for seven minutes until rice becomes slightly tender outside.

Pour rice carefully into a colander. Rinse lightly with warm water to stop extra cooking immediately after boiling.

Mix saffron threads with warm water inside a small bowl. Let the saffron release beautiful color and flavor.

Combine yogurt, egg yolk, and one cup cooked rice inside a bowl. Mix until creamy and evenly combined.

Place a nonstick pot over medium heat. Add oil and butter until melted and lightly hot inside.

Arrange potato slices evenly across the bottom of the pot. These slices create extra crispy golden tahdig texture.

Spread the yogurt rice mixture gently over potatoes. This layer helps form the famous crispy Persian rice crust.

Pile remaining rice into the pot carefully. Shape it like a small mountain for proper steaming while cooking.

Mix a few tablespoons of rice with saffron water. Spoon saffron rice over the top for beautiful color.

Wrap the pot lid with a clean towel. Cover tightly and cook on low heat for forty minutes.

Turn off the heat carefully. Let the rice rest five minutes before flipping onto a serving platter beautifully.