Pork and mushrooms in oyster sauce

Ingredients:
1 kilo pork, you can use shoulder or butt part
3 cups water
3 tbsp oyster sauce
1 tbsp Worcestershire sauce
1/2 cup button mushrooms, sliced
1/2 cup cream of mushroom
1 tbsp butter
1 tbsp minced garlic
2 tbsp sliced onion
salt and pepper to taste

Procedure:
Cut pork into cubes and boil in 3 cups of water, oyster sauce, and Worcestershire sauce until tender.  Add water as necessary while it is boiling.  When the pork is tender, remove from heat and let it cool.  Once cooled, slice pork in about 1/3 inch thickness, set aside.  Reserve the sauce where the pork was boiled.  Saute garlic and onion in butter.  Add in the mushrooms.  After a few minutes, when the mushroom is cooked, add in the cooked pork and reserved sauce.  Stir and let boil for a few minutes.  Add in the cream of mushroom.  Season with salt and pepper and continue to cook until pork is very tender and sauce has thickened.  Best served with rice.