Bring a large pot of water to a boil, then add the lo mein noodles. Cook for 2-3 minutes until just al dente, then drain and toss with a teaspoon of oil to prevent sticking. Set aside.
Prepare your vegetables by julienning the carrots, thinly slicing the bell pepper, trimming the green beans, and mincing the garlic and ginger. Keep everything nearby for quick stir-frying.
Heat the wok over high heat until shimmering, about 2 minutes. Add a tablespoon of vegetable oil and swirl to coat the surface.
Add minced garlic and grated ginger to the hot oil. Sauté for about 30 seconds until fragrant, watching for a bubbly aroma and a slight sizzle.
Next, toss in the julienned carrots and trimmed green beans. Stir-fry for 2-3 minutes until they start to soften but still retain their bright color and crunch, listening for a crackling sound and watching for slight blistering.
Stir in the sliced bell peppers and continue stir-frying for another 2 minutes until the peppers are blistered and fragrant, and all vegetables look lively and slightly charred on edges.
Push the vegetables to one side of the wok. Pour in the soy sauce, oyster sauce, and sesame oil. Let the mixture bubble and thicken slightly, about 1 minute, stirring constantly to coat the vegetables evenly.
Add the cooked noodles to the wok and toss everything together quickly with tongs. Stir-fry for 2 more minutes until the noodles are heated through, glossy, and coated in the savory sauce, with vegetables evenly distributed.
Taste and adjust the seasoning—add more soy or a splash of rice vinegar if desired. Remove from heat once the dish looks vibrant, glossy, and fragrant.
Serve immediately, garnished with toasted sesame seeds and sliced scallions if you like. Enjoy hot, with the vegetables crisp and the noodles tender and flavorful.
