Pork tenderloin is braised in black tea and marinade in the soy sauce based sauce.
In a medium pot, bring the water to a boil and drop the tea bags. Simmer for 3 minutes and remove the tea bags. Take 1/2 cup of the tea from the pot and set aside. Add the pork tenderloin to the pot and bring back to the boil. Remove the scum, cover, and cook for 30-40 minutes at low heat. Remove from the heat and leave the meat in the tea for 10 more minutes.
In a small pot, heat the 1/2 cup of tea saved earlier and the rest of the ingredients for the marinade. Bring to a boil and turn off the heat.
In a food storage bag, add the pork and the marinade. Marinate the meat in the fridge for at least 4 hours or overnight. Slice into 1/2" to 1" thick and serve.