This Thermomix recipe for sweet and sour chicken stir-fry is a delicious and easy way to enjoy this classic Chinese dish. The chicken is marinated in a tangy sauce made with vinegar, ketchup, soy sauce, and sugar, giving it a perfect balance of sweet and sour flavors. The chicken is then stir-fried with colorful bell peppers, pineapple chunks, and onions, creating a vibrant and flavorful dish. Serve it over steamed rice for a complete meal that the whole family will love.