The flavor of this everyday, Gujarati-style dal comes from the pure nuttiness of split pigeon peas, boiled until tender and bolstered with spices bloomed in hot ghee. This fat-tempering technique, called vaghar in Gujarati, has many names and many uses across the country. In this case, the tempering is a great introduction to the resourcefulness and finesse of Indian home cooks: Just a few tablespoons of carefully seasoned fat, tipped in at the very last moment, transform an entire pot.