Beat the egg. Heat the oil in a pan until hot, then add the egg and scramble until cooked. Remove the egg from the pan and set aside.

Sauté the onion, carrot, and shiitake mushroom. If the pan gets too dry, add a little water. Add 1 tablespoon of soy sauce and 1/2 teaspoon of sugar. Cook until the onion starts to turn translucent.

Add the cold rice to the pan and stir-fry with the cooked vegetables. Add the remaining 2 tablespoons of soy sauce and mix well. Return the cooked egg to the pan, add the pickled ginger, and stir everything together. Serve hot.