Melt the butter in a saucepan over a medium to low heat. Add the cinnamon, cardamon pods and peppercorns and gently fry the spices for about 4 minutes until fragrant.
Add the drained rice to the butter and stir to coat for a minute. Increase the heat to medium high and if you are using pistachios and/ or barberries stir them in.
Pour enough water over the rice to cover by about 1 cm and season with salt. Rest some greaseproof paper on the surface of the water then place a lid on the pan, bring to the boil and simmer for 5 minutes.
Lift the lid and paper off the pan and drizzle the saffron water evenly over the rice. Replace the paper and lid, turn down the heat to medium low and cook for a further 4-5 minutes.
Serve with the crispy onions on top and seasoned yoghurt on the side.