Cook the chow mein noodles according to the package instructions until al dente. Drain and rinse them under cold water to stop the cooking process. Toss the noodles with 2 tablespoons of vegetable oil and 1 teaspoon of sesame oil to prevent sticking. Set aside.
In a bowl, whisk together soy sauce, hoisin sauce, rice vinegar, maple syrup (or agave nectar), cornstarch, and vegetable broth (or water) until well combined. Set the sauce aside.
Heat 2 tablespoons of vegetable oil in a large wok or skillet over medium-high heat. Add minced garlic and grated ginger, and stir-fry for about 30 seconds until aromatic.
Add the sliced onion, julienned red bell pepper, and carrot to the wok. Stir-fry for 2-3 minutes until the vegetables start to soften.
Add the shredded cabbage and bean sprouts to the wok. Continue to stir-fry for another 2 minutes until the vegetables are tender-crisp.
Pour the prepared sauce over the stir-fried vegetables in the wok. Toss everything together until the vegetables are coated evenly with the sauce.
Gently add the cooked and prepared chow mein noodles to the wok with the vegetables and sauce. Use a pair of tongs to carefully mix and coat the noodles with the sauce and vegetables. Be gentle to avoid breaking the noodles.
Once the noodles are heated through and well combined with the vegetables and sauce, remove the wok from the heat.
Serve the Cantonese-style Vegan Chow Mein in individual plates or bowls. Garnish with sliced green onions for added freshness and color.