In a mortar pound the peppercorns until finely ground. Add the garlic and coriander roots and pound everything together until a homogenous mass forms. Set aside.
Heat the vegetable oil in a heavy-bottom large pot over medium high heat. Add the garlic-coriander-peppercorn mix and fry until fragrant.
Add the pork. Fry, stirring often, for about 5 minutes, or until the pork is browned on all sides.
Add the soy sauces. Keep stirring to help the pork absorb the saltiness.
Add the water, tofu, palm sugar and 5 spice powder. Add a little more water if necessary, to barely cover the meat and tofu. Bring to a gentle boil. Let simmer with the lid almost closed until the pork shoulder is tender, about 60-90 minutes.
When the pork is tender add the eggs and let them simmer in the broth for a little while longer.
Taste the broth. It should be more sweet than salty, but not cloyingly so. There should be a nice aroma of star anise and cinnamon from the 5-spice powder too. Serve with lots of rice and some sliced cucumbers or pickled mustard greens.