Procedure:
1- Wash rice several times until water runs clear. Then soak rice with half of the salt to taste for at least an hour.
2- Meanwhile, place the ground saffron in a cup and fill one-quarter of the cup with hot water. Set aside.
3- Bring a pot of water to a boil then add the rest of salt and add drained rice.
4- Boil the rice for 10–15 minutes or bite a few grains; if the rice feels soft, it is ready to be drained. You don't want to boil it until its completely soft cause it will make the rice grains stick together later when you serve. The perfect time to drain the rice is when the grains are soft on the outside and a bit hard inside. This is a step that plays the main rule on how good the rice will look when served. Once it's the right time drain rice in a large, fine-mesh colander. Note: Do not stir the rice while boiling
5- Put the pot back on the stove and add 2 tbsp of butter. Slice the potatoes or cut them in any shape just like the picture and lay them in the base of the pot. Potatoes will protect the rice from sticking to the bottom of the pot, but also to create a delicious edible crust of rice and potato.
6- Top with the drained rice and cover with a lid. Cook until the rice begins to steam (about 3–5 minutes), then turn the heat to low. Add one table spoon of butter on the to of rice and let the rice cook for one hour covered over low heat.
7- Heat two tablespoon of the butter in a frying pan. Drain barberries and add them to the pan. Add the sugar and one tablespoon of saffron and give it a nice stir so that the barberries are coated with butter and sugar. This should not take more than one or two minute. Note: Keep the heat low because barberries burn easily.
8- Take 4 or 5 table spoon of the rice out and mix with barberries and the remaining saffron water. Set aside for use as garnish.
Place the white rice on a serving plate and add the rice mixed with saffron and barberry on the top. add the potato crust to the dish and serve.