Turn the heat to medium, and add the noodles to the pan along with 1-1/2 tablespoons of the prepared sauce. Stir-fry until the noodles are soft, 3 to 4 minutes.
Remove the noodles onto a plate. In the same pan, stir fry the onion for a minute, and then carrot and mushrooms until wilted. Add a tablespoon of water if the vegetables look dry.
Add the seafood and the remaining sauce, and stir-fry until the seafood is cooked through. Follow this by the scallion and optional enoki mushrooms until the scallions are slightly wilted.
Add the seafood and the remaining sauce, and stir-fry until the seafood is cooked through. Follow this by the scallion and optional enoki mushrooms until the scallions are slightly wilted.