In downtown Manaus, the city considered the capital of the Brazilian Amazon, just one restaurant exclusively serves indigenous foods made by the rainforest’s native people. At Biatüwi, diners can enjoy fish stews, maniwara ants, and guaraná, which is juice traditionally extracted from the red Amazonian berry by using a local fish’s tongue as a grater. Run by a husband and wife, it is Brazil’s first official restaurant to serve only indigenous food and be owned by indigenous people—even though the indigenous population is more than 800,000 inhabitants among 300 different…