- Place shiitake mushrooms in medium bowl, and add boiling water.
- Cover with small plate.
- Set aside 30 minutes.
- Drain mushrooms, reserving soaking liquid.
- Remove and discard stems from shiitake mushrooms.
- Slice mushrooms into strips, and set aside.
- Place mushroom soaking liquid into measuring cup, adding water if necessary, to make 2 cups.
- Add soy sauce to mushroom liquid.
- Set aside until ready to use.
- In medium saucepan, heat oil over medium heat.
- Add onion, and cook, stirring often, until golden brown, about 9 minutes.
- Add sugar, thyme, button mushrooms and reserved shiitakes, and cook, stirring occasionally, until button mushrooms are tender, about 4 minutes.
- Add flour, and cook, stirring occasionally, 1 to 2 minutes.
- Whisk in reserved mushroom liquid, and cook, stirring continuously, until thickened, 5 minutes.
- Stir in parsley, and add salt and freshly ground pepper to taste.
- Serve hot.