What does nostalgia taste like? Does it come on in a rush, or linger gently? In a country so utterly deep-fried in culinary folklore and history, but also avidly sampling a global catalogue of tastes, the answers can be piquant and many. One set comes from First Food, an initiative of the Delhi-based Centre of Science and Environment. Putting neglected culinary secrets back on the map, the engaging, 168-page book stirs memories of piping hot jute pakoras and other leaf preparations of a Bengal before partition, of the fermented kanji vada evoking images of Holi festivities in northern parts of India, and among other delights, of the simple yet rarely found dishes made using tender bhang leaves.