Place lentils, ginger, bay leaves and cinnamon in a large saucepan with 3 cups of cold water. Bring to the boil, reduce the heat to medium and simmer, stirring to prevent sticking for 10-12 minutes. Discard spices and set aside.
Heat the butter in a large frying pan over a medium high heat. Add the onion and cook for 3 minutes. Stir in the garlic, turmeric, cumin, garam marsala and chilli flakes and cook for a further minute or until fragrant. Stir in the lemon juice and season to taste with salt.
Add the lentils to the pan and mix well. Cook for a further 3 minutes, stirring constantly. Remove from the heat. Stir in coriander and serve steamed rice and natural yogurt.