Cook the noodles: Boil according to package directions until just tender.
Drain and rinse under cold water to stop the cooking. Toss with a drizzle of sesame or neutral oil to prevent sticking.
Prep the veggies: While the noodles cook, shred the cabbage, slice the pepper and green onions, and prep the carrot and cucumber. Keep everything bite-sized for easy eating.
Make the dressing: In a bowl, whisk peanut butter, soy sauce, lime juice, rice vinegar, honey, sesame oil, ginger, garlic, and sriracha.
Add warm water, 1 tablespoon at a time, until it’s pourable and silky. Taste and adjust salt, lime, and heat.
Toss the base: In a large bowl, combine noodles, cabbage, carrot, bell pepper, green onions, and herbs. Add about two-thirds of the dressing and toss well so the noodles are evenly coated.
Add protein (if using): Fold in chicken, shrimp, tofu, or tempeh.
Add more dressing as needed to coat everything lightly.
Add crunch: Sprinkle in chopped peanuts and sesame seeds. Toss gently again.
Finish and taste: Squeeze in extra lime, add a pinch of salt if needed, and adjust heat with a little more sriracha. The flavors should be bright and balanced.
Serve: Top with more herbs, peanuts, and crispy shallots if you like.
Serve chilled or at room temperature with lime wedges.