Wah hasene, if put oyster sauce, will it become very chinese
cuisine taste? I now trying to work out my own mushroom and bacon
sauce. US potato uh. Okay, I will try to shop for it later. lol. I
usually don't take note of where my potato come from.
FireIce, if use blender, the texture of the mash potato would be
different. Too nua and slimy I don't like. I prefer rough texture.
Just that doing it manually seems abit stupid to me. 
My overseas friend told me that there are ready made gravy for
mashed potato available in the west.
Unfortunately, I could not find it in Singapore. However,
this friend recommended milk for preparation, use fork to mash the
potato.