Step 1

Melt the butter in a medium saucepan and stir in the rice, making sure the grains are well coated. Add the boiling water, a teaspoon of salt and some white pepper. Mix well, cover with a tight-fitting lid and cook on a very low heat for 15 minutes. Don't be tempted to uncover the pan – you need to let the rice to steam properly.

Step 2

Remove the pan from the heat – all the water will have been absorbed by the rice – and pour the saffron water over about a quarter of the surface, leaving most of the rice white. Cover with a tea towel, reseal tightly with the lid and set aside for five to 10 minutes.

Step 3

With a large spoon, transfer the white rice to a large bowl and fluff it up with a fork. Drain the barberries and stir them in, followed by the herbs and most of the pistachios, reserving a few to garnish. Fluff up the saffron rice in the pan, then fold gently into the white rice – don't overmix: you don't want the white grains to be stained by the yellow ones. Taste, adjust the seasoning and transfer to a shallow serving bowl. Scatter the remaining pistachios on top and serve warm or at room temperature.