- In a vessel, add buttermilk, add green chilli paste, mix everything well and rest it aside. For tempering: In a wok, add oil and heat it. Add cumin seeds, mustard seeds and allow it to pop up. Add dried red chillies, stir well. Add curry leaves and let them crackle. Add finely chopped onions, add turmeric powder, mix Switch off the flame. Transfer the buttermilk into the tadka. Garnish with coriander leaves. Serve hot with rice!!!