a handful of blanched, skinned baby broad beans (optional)
a handful of blanched peas (optional)
Rinse the rice in a sieve under cold running water until the water runs clear; put to one side.
Heat the olive oil in a large, heavy-bottomed pot and throw in the onions. Cook over a medium heat until they soften and turn golden.
Season the chicken thighs and add them to the pan. Brown on all sides, then pour in 570ml/1 pint water and bring to a simmer. Cover with a lid and cook until the chicken is tender, about 20 minutes.
Meanwhile, peel the zest from the orange with a potato peeler, then cut it into matchstick strips. Blanch in a little pan of boiling water for a couple of minutes, then drain.
Dissolve the sugar in 110ml/3½fl oz water in a small, heavy-bottomed pan over a medium heat, then bring to the boil and let bubble to reduce and thicken for 5–10 minutes until syrupy.
Add the orange zest, flaked almonds and pistachios and boil for 5 minutes, skimming off any froth. Strain the syrup and return to the pan; set aside the orange zest and nuts. Add the saffron and rosewater to the syrup and boil again for 3 minutes, then add the cardamom seeds.
Preheat the oven to 150°C/Gas mark 2. Strain the stock from the chicken thighs and add the syrup to it. Make this up to 570ml/1 pint with more water. Bring it to the boil in a large pan and add the rice.
Season and add two-thirds of the orange zest and nuts, keeping the rest to one side. Bring back to the boil, then cover and simmer until the rice is cooked. The liquid should have all been absorbed by this stage.
Bury the chicken and onion in the rice pot and add the broad beans and peas if you are including them. Put the lid on and cook in the oven for 20 minutes.
Serve straight from the pot or, if you prefer, in a large, warmed serving dish.
Sprinkle the last third of the orange zest and nuts over the top before bringing it to the table.