Put the saffron threads into a small bowl of hot water and allow to soak.
Heat the vegetable oil in a large saucepan with a low heat. Add the onions and cook for 5 minutes, stirring.
Add the butter, cumin, cinnamon, salt, pepper, paprika and bay leaves and cook for two minutes, stirring constantly.
Add the rice and continue to stir for three minutes.
Add the saffron and stock. Bring to the boil then simmer for 20-25 minutes, or until all liquid has been absorbed. If necessary, add a little more stock and cook until rice is tender and all the liquid has been absorbed.
Discard the bay leaves, season, stir through the cashews and serve.