I've lived in India almost all my life and I've never heard of Ashwagandha being part of any of the traditional culinary systems of India. Cooking with Ashwagandha seems to be a recent Internet trend exclusively. Traditionally, as Ayurvedic medicine, it would either be swallowed in powder form with milk or ghee, or brewed as a tea/kadha. I've grown up eating dal everyday, and we really don't put any Ashwagandha in it.