This is one of the favourites of the people of the Central Travancore region of Kerala. It is an easy to make curry for rice and does not need any masala.
Take curds that are not too sour and add some water to dilute it. In a tava or wok, splutter some mustard seeds and then saute ginger, green chillies, curry leaves and garlic in the same oil. Add the prepared buttermilk into the tava along with salt and a little turmeric powder. Heat and take off the fire without allowing the buttermilk to boil.