While boiling the linguini, Garten sautees red onion in some butter and oil. Once tender, Garten likes to add a lot of garlic and red pepper flakes. “Give it a little bit of heat,” she said.

But Anachere is a two-day trip from San Borja by motorized dugout canoe, so the Tsimane living there still get most of their food from the forest, the river, or their gardens. I’m traveling with ...