Put the rice into a sieve and rinse it in water until the water runs clear. Heat the butter in a heavy-bottomed saucepan and sauté the onion until soft and pale gold. Add the garlic and cook for another couple of minutes. Now add the rice and stir it around until it is well coated in the butter and just beginning to toast. Add the cranberries and 250ml of the chicken stock and bring up to the boil.
Cover and simmer over a medium heat until the rice is tender. The stock should become absorbed as the rice cooks. Make sure, by gently forking the rice, that it is not sticking to the bottom of the pan – if it is, add a little more stock. The rice should cook in about 30 minutes but it does depend on your heat. Brown rice never softens as much as white rice – it will still be a little firm in the centre and ‘nutty’ – and wild rice stays even firmer.