My sister Lalitha’s classmate, Smita, a Gujarati, is an amazing cook. She can create vegetarian magic with minimal ingredients to balance sweet, hot, and nutty flavors in one lentil-based mouthful. I sampled this dal at Smita’s kitchen table in Ohio, and its spicy-pungent memory lingered for weeks. Serve it with a basket of pooris and the mango puree (Aamras;).