Sweet and Sour Pineapple Pork is a classic Chinese dish that is both tangy and sweet. To make this recipe, start by marinating thinly sliced pork in a mixture of soy sauce, vinegar, and sugar. In a hot skillet or wok, stir-fry the marinated pork until it is cooked through and slightly browned. Then, add pineapple chunks, bell peppers, and onions to the skillet and continue stir-frying until the vegetables are tender. In a separate saucepan, combine pineapple juice, ketchup, vinegar, sugar, and cornstarch to make the sweet and sour sauce. Pour the sauce over the stir-fried pork and vegetables, and cook until the sauce thickens and coats the ingredients. The result is a deliciously tangy and sweet dish that pairs perfectly with steamed rice.