 As part of the last leg of the Columbian Exchange, Spanish and Portuguese traders began introducing foods from the New World to China through the port cities of Canton and Macau.Mexican chili peppers became essential ingredients in Sichuan cuisine and calorically-dense potatoes and corn became staple foods across the northern plains.During the Qing Dynasty, Chinese gastronomes such as Yuan Mei focused upon a primary goal of extracting the maximum flavor of each ingredient.