Cassava and potato simmered with beef or chicken until the cassava starts to break down and thickens the broth. It is the everyday Colombian soup: forty-five minutes in a pressure cooker and open to whatever else is in the fridge. Serves four.
Arracacha is a good addition if you can find it: an Andean root, somewhere between celery root and parsnip, sold frozen in some Latin groceries. Carrot, plantain, corn on the cob or pumpkin all work too. This is a soup that takes whatever is in the fridge.