Cook ramen noodles as directed on package. Drain well, reserving cooking water.
Melt butter in medium saucepan on medium heat. Add garlic powder, oyster sauce, fish sauce, soy sauce and 1/ 2 cup of the reserved cooking water, whisking to mix well.
Add cooked noodles, Parmesan cheese and green onions, tossing to coat noodles. Add additional cooking water 1 tablespoon at a time, as needed until desired consistency is reached. Serve immediately, sprinkled with additional grated parmesan, if desired.
