Bring water to the boil in a large pot. Add salt and rice. Bring back up to the boil then cook for 5 minutes. Drain and leave to steam dry for 5 minutes.

Melt butter in a small pan over medium heat. Add barberries and cook for about 1 1/2 minutes until they plump up (see video!).

Remove from heat (they will shrivel quickly) then stir through rose water (if using).

Preheat oven to 200C/390F (standard) or 180C/350F (fan).

Lightly grease a glass pie dish with oil.

Ground saffron into powder (optional step). Add water and leave to seep for 10 minutes.

Mix yogurt, egg, oil, saffron water and salt in a large bowl.

Add rice, stir well.

Pour half the rice in the pie dish, smooth surface. Top with 1/3 of the barberries.

Cover with remaining rice, smooth surface, sprinkle over another 1/3 of the barberries. Press down firmly, cover with foil.

Bake 60 - 80 minutes until the crust is deep golden all over.

Rest for 10 minutes. Remove foil. Place serving plate on pie dish then flip upside down (it won't stick because of the oil, see video!).

Scatter surface with remaining barberries then serve.