Cassava with Warm Pickled Onions

Yuca is among the most commonly eaten viandas—the local Puerto Rican word for starchy fruits and vegetables, such as plantain and taro. It’s also among the most common root vegetables across the tropics, a fixture as much in Madagascar as in Vanuatu. It’s believed to have been among the principal foods of the indigenous Taínos of the Caribbean. This is my grandmother’s recipe. She never wrote it down, but my mother had it deep in her memory, and we cooked it together for this version. The o