Wash the rice, drain, and transfer to a zip-loc bag or freezer-safe container. Leave it in the freezer for at least 8 hours.
Marinate the pork with the cornstarch, oyster sauce, and vegetable oil for about 15 to 20 minutes.
Meanwhile, in a medium pot, bring 7 cups of water to a boil. Add the frozen rice (no need to defrost) and bring it to a boil again, stirring the rice to prevent sticking. Reduce the heat to a low simmer, and cover and cook for about 15 minutes. Periodically check and stir the congee. It’s important to stir from the bottom to prevent sticking, as the rice texture thickens quickly.
While that’s cooking, dice the thousand year-old egg and set it aside. Very thinly julienne the ginger. Don’t prepare this ahead of time, as we want the flavor of freshly cut ginger.
After 15 minutes, it’s time to add the julienned ginger, pork, and thousand year-old egg. Stir and simmer for another 5 minutes or so. Finally, stir in the white pepper and salt to taste. Serve piping hot with chopped scallions and cilantro.