Pour the oil into a large wok or skillet set over high heat. When hot, add the pork. Stir well, and cook until there is no more pink, about 3 to 5 minutes.
Remove the pork with a slotted spoon and set aside.
Add the mushrooms and shallots. Stir well, and cook them until soft, about 3 to 5 minutes. Turn down heat if they look like they will burn.
Add the pork back to the wok.
Pour in the sake, and dislodge any browned bits on the bottom with a wooden spoon. When the sake has evaporated add the soy sauce. Cook for 1 minute, then turn off the heat.
Meanwhile, cook the soba noodles according to the directions on the pack.