1. Cook noodles: Prepare noodles according to package instructions but reduce cooking time by about one minute to avoid sogginess. Reserve some cooking water before draining.

2. Make sauce: Whisk together gochujang paste, toasted sesame oil, soy sauce or tamari, mirin or vinegar, brown sugar or honey, and gochugaru if using. If the sauce is too thick, thin with a few tablespoons of reserved noodle water.

3. Sauté aromatics and vegetables: Heat neutral oil in a large pan or wok over medium-high heat. Add scallion whites, garlic, and ginger; cook for 1–2 minutes until fragrant. Add bell peppers (if using) and cook briefly. Then add Napa cabbage or other chosen vegetables; season with salt and pepper and stir-fry for about 3 minutes until tender but still crisp.

4. Combine noodles and sauce: Add the gochujang sauce and toasted sesame seeds to the pan, letting it sizzle briefly. Add cooked noodles and toss thoroughly to coat. Add reserved noodle water as needed to loosen the sauce and help it cling to noodles.

5. Finish and serve: Remove from heat, stir in fresh Thai basil or cilantro, and drizzle with toasted sesame oil. Garnish with reserved scallion tops and additional sesame seeds. Serve with optional lime wedges on the side.