Bring plenty of water to a boil in a large pot. Add the tea bags and the block of pork, and simmer for 40 minutes to an hour.
Put all the ○ ingredients into a separate pot and bring to a boil. If you don't like a sour taste, use less vinegar.
Marinate the tea-simmered pork in the pot you made the sauce in (or you can marinate in a bowl or a plastic container).
Slice the pork just before eating. Serve with a little of the sauce spooned over, and done!
If you marinate hard boiled eggs (cooked from water for 12 minutes) with the pork, they turn into ajitama (flavored eggs) and are delicious.
Story Behind this Recipe
This black tea simmered pork is my mother's recipe. I phoned her and wrote down the instructions and tried it out. I uploaded it here to record it for myself.
Try wrapping the pork with the marinade in lettuce leaves with kimchi and mayonnaise. You can also use it instead of char siu pork, and in bentos too. Stored in a closed plastic container in the refrigerator, it lasts for at least 3 days. If you cut it up into small pieces and leave it in the marinade it gets salty, so I recommend just slicing off what you need each time!