Heat 2 tbsp of the ghee in a large frying pan over a medium heat. Cook the onion for 6-8 minutes or until soft. Add the beans, and cook, stirring regularly, for 15-20 minutes or until they are completely soft. Add the garlic and cook for a further 10 minutes. Mix in the turmeric and cinnamon, then season generously. Mix in the tomato purée and cook for 5 minutes. Stir in the butter, then take the pan off the heat. Tip in the rice and fold together gently, avoiding breaking the rice grains, until evenly combined.