Bake onions for about 20-25 minutes. Mushrooms, and tofu for about 30-35 minutes.
Meanwhile, bring a large pot of water to boil (to cook vermicelli.)
ou can add a tbsp of sesame oil and a tbsp of soy sauce to vermicelli cooking water. Noodles are less sticky this way.
After tofu and frozen and then defrosted, the texture will turn more chewy and spongy.
If you can't find Korean vermicelli, you can use a different type of noodle and follow the package direction.