Cook your noodles according to package instructions (mine required about 6 minutes in boiling water). Give them a good rinse under cold water to keep them from overcooking. Set them aside.
While the noodles are cooking, make the sauce by whisking together the two different soy sauces, vegetarian oyster sauce, Shaoxing cooking wine, sugar, white pepper, and corn starch in a small bowl.
When the noodles are done, add oil to a wok or large, deep skillet over medium-high heat. When the oil begins to shimmer, add the onion and garlic and sauté until fragrant (around 2 minutes). Next add the carrots, broccoli, potato, and lotus roots. Continue sautéing until the carrots and broccoli start to turn very bright (around 3 minutes). Next, add the cabbage, bean sprouts, bamboo shoots, tofu, sweet pepper, and snow peas. Continue sautéing until bean sprouts begin to turn translucent (around 2 minutes).
Lower your heat to low and add the cooked noodles to your wok, together with your sauce. Stir vigorously to ensure that everything is well combined and evenly coated. Your noodles will likely be a little dry so add 1/4 cup of the veggie broth while you continue to stir. Continue adding more vegetable broth, 1/4 cup at a time, until the noodles are slick (not sticky). Remove from heat and drizzle with sesame oil and chili oil (if using).