Folklorist Berta Montero Bascom of Havana used to bring a vat of these beans, expected and appreciated, to any occasion where food was shared. Below is Berta’s family recipe recounted as we cooked them together in her Berkeley kitchen. This is a dish you can and perhaps should make days ahead. Quantities are elastic, and you can halve or expand this recipe without running into trouble. Two pounds of beans will serve 15-20 people depending on what else you’re having.