Heat 1 tablespoon oil in a wok over high heat. Add the onion, capsicums and carrot and stir-fry for 1-2 minutes or until slightly softened. Pour in the prepared sweet and sour sauce and bring to boil. Once boiling, turn heat off and add all the fried pork and the pineapple pieces. Toss well to coat. Transfer to a serving platter or plates and serve immediately. Enjoy :)