Cook the thin wheat noodles according to package directions; drain, toss lightly with a little oil to prevent sticking, and set aside.
In a small bowl, whisk together the soy sauce, hoisin sauce, rice vinegar, honey, 2 tablespoons sesame oil, ground ginger, and black pepper; add miso or spicy sauces if using and set the sauce aside.
Heat the large skillet over medium-high heat and add the olive oil and the remaining 2 tablespoons sesame oil.
Add the chicken pieces and cook, turning occasionally, until about 90% cooked through, about 4–5 minutes.
Add the minced garlic and cook for about 1 minute, stirring, until fragrant.
Add the broccoli, sliced carrots, sugar snap peas, drained baby corn, and optional bamboo shoots or water chestnuts; pour the prepared sauce over the vegetables and chicken, stir to combine, cover, and cook about 3 minutes until vegetables are crisp-tender.
Turn off the heat, add the cooked noodles (in batches if necessary), and toss well to combine with the chicken, vegetables, and sauce.
Garnish with sliced green onions, add additional soy sauce to taste if desired, and serve immediately.