
In a small bowl, stir together the sesame oil, light soy sauce, dark soy sauce, oyster sauce, and mirin until smooth.
Cook the fresh noodles according to the package directions until just tender. Drain well, then rinse briefly under cold running water to stop the cooking and prevent sticking.
Heat the oil in a large wok or deep nonstick skillet over high heat. Add the white parts of the green onions and cook for about 20 seconds, then add the garlic and stir-fry for 10 seconds until fragrant and lightly golden.
Add the drained noodles to the pan, then pour in the sauce. Toss continuously for 1 to 2 minutes, letting the noodles absorb the sauce and lightly caramelize in spots.
Add the green parts of the green onions and toss for 20 seconds, just until wilted. Serve immediately while hot.