Bring a large pot of water to boil. You don't need to salt the water for Asian noodles.
While the water is heating up, slice the scallions lengthwise then cut them into one-inch pieces. Separate the green parts of the onions from the white parts. Set aside.
Slice cabbage into shreds, wash bean sprouts, chop bok choy or spinach very roughly. Chop broccoli, julienne carrots or any other vegetables you are using. Set aside.
In a small bowl, combine the oyster sauce, soy sauce, sugar, minced garlic, red pepper flakes, and 1 teaspoon of sesame oil. Stir to combine. Set aside.
In a small bowl or ramekin, mix the canola oil and toasted sesame oil.
When the water comes to a boil, add the noodles and boil for 2-3 minutes (according to package directions). Do not overcook, they are better al dente. Drain and rinse with cold water. Leave in the strainer until ready to use.
Heat a wok or large skillet over high heat. Let the skillet heat for several minutes until it becomes very hot.
Drizzle in 2 Tbsp combined sesame and canola oil. When the pan becomes very hot again and the oil starts to shimmer, add the noodles and spread out to a thin, even layer. Gently swirl the pan so the oil evenly coats all the noodles. Cook the noodles for 5-6 minutes or until they become golden and lightly crisp.
Flip the noodles over, in sections if necessary, using a large spatula. Pour 2 more tablespoons of sesame/canola oil mixture around the outside edges of the noodles and swirl the pan to allow the oil to evenly coat the noodles. Let the noodles fry for an additional 3-5 minutes. Remove the noodles to a plate.
In the same skillet or wok, heat remaining oil. Add the white part of the scallion and let sizzle for just a few seconds. Add the shredded carrots, broccoli, and any other chopped vegetables you are using, and let cook for an additional 30 seconds. Add the noodles back into the skillet and toss. Separate the crispy parts of the noodles with a fork or pair of tongs to remove any that are stuck together.Pour on the soy sauce mixture. Toss until the sauce evenly coats the noodles. Garnish with remaining green onion tops and mung bean sprouts. Serve hot.
Note: This recipe is totally adaptable. Add any fresh, crunchy vegetables that you have on hand. More or less of any that are listed. Make it your way. If you want to add an animal protein, just toss with grilled chicken or shrimp.