Yams vs sweet potatoes: the difference, nutrition and how to cook them

Widely known as Sam the Cooking Guy, Sam Zien is an enthusiastic proponent of sweet potatoes. He loves mashing them and seasoning with miso, butter and chopped spring onions. Or he cubes, boils and roasts the sweet potatoes, then adds a generous dollop of lemon yogurt, with sprinkles of dukkah, a mixture of chopped nuts and sesame seeds, seasoned with cumin, coriander and salt. Another way is to add sweet potatoes to quesadillas with Mexican chorizo, a highly seasoned fatty pork sausage, and...