Salad of Oca, Radish, and Red Onion

This recipe, from one that the author-historian-restaurateur Maricel Presilla collected while assembling her forthcoming book about the foods of Latin America, hails from the highlands of Ecuador. There, it is prepared with ulluco (Ullucus tuberosus), another colorful, shiny tuber we would be lucky to add to North American markets. She serves the bright-hued mixture of softly sweet oca rounds and sharp, crisp radish coins at room temperature with grilled meat or fish. For a lovely pr