Season the pork shoulder block with salt and pepper.

Brown all surfaces of the pork shoulder in a frying pan over medium-high heat.

Place the browned pork shoulder into a pot.

Add water until the meat is just barely covered.

Add the soy sauce, sake, mirin, and grated ginger to the pot.

Bring the mixture to a boil, then reduce the heat to low and simmer for 1 to 1.5 hours, or until the meat is tender.

Once the meat is tender, increase the heat to high and boil for 10-20 minutes to thicken the sauce.

Continue boiling until the sauce has reduced by about half.

Remove from heat and allow to cool.

Wipe away any solidified grease from the cooled sauce.

Serve the Char Siu sliced over rice to make a char siu rice bowl.

Alternatively, use it as a topping for ramen.