Dal is as common in India as mashed potatoes are in Minnesota. The word means dried legume, as in lentil or pea. Or chickpea or fava bean. An edible seed that grows in a pod and is hulled and split.

When it comes to South Indian cuisine, dosa is one of the most popular dishes, made from a fermented batter of rice and urad dal (split black gram). It’s a thin, crispy pancake that’s cooked on a ...