Cut the cooked pork into small dices. Cut the yellow capsicum into small pieces. Discard the leaves from the celery. Rinse the celery and cut into 1-cm lengths. Separate the cold rice into individual grain.
Heat a wok, add the oil, and heat until 170 degrees C over high heat. Add the peppers and celery, and stir-fry until soft. Add the salt and rice and stir-fry vigorously for about 1 minute to mix the ingredients well. Turn the heat to medium. Add the pork and stir well.
Stir-fry the diced pork until the oil from the fat meat is rendered. Season with MSG and transfer to a serving dish.