Prep:

1. Marinate the chicken: Thinly slice the chicken breasts into bite-sized pieces and add to a medium bowl. Add the white pepper, kosher salt, low sodium light soy sauce, Shao Xing rice wine and sesame oil. Mix well to coat, set aside to marinate while you prepare the rest of the ingredients.
2. Make the sauce: Whisk together the low sodium light soy sauce, oyster sauce, Shao Xing rice wine, chinkiang vinegar, sesame oil, pure chili oil and white sugar in a small bowl or measuring cup (for easier pouring) until combined well.
3. Prepare all the fresh ingredients: Prepare the spring onion, garlic, ginger, fresh red chilies (if using) and baby bok choy as indicated in the ‘ingredients’ section.

Spicy Udon Noodles Stir-Fry:

1. Prepare the noodles: Bring a small pot of water to a boil. Lower the heat to medium-low and place the udon noodle cakes in the pot of hot water. Use tongs to hold onto the noodle cakes and gently shake until the noodle strands have separated and are tender – about 1-2 minutes. Drain into a colander and run cold water on the noodles to prevent sticking and halt the cooking process. (If using frozen or dried udon noodles, prepare according to package instructions.)
2. Cook the chicken: Heat 1 teaspoon peanut oil in a large nonstick wok (or heavy bottomed deep skillet/frying pan) over high heat. Add the marinated chicken and immediately spread the pieces out in the wok. Allow to sear for 30-40 seconds, then flip the pieces and sear the other side for another 30 seconds. Stir fry for a minute or until just cooked. Transfer to a clean bowl and set aside.
3. Stir-fry the aromatics: Heat the remaining 1 tablespoon of peanut oil in the wok over medium-high heat. Add the spring onion white and light green parts and stir-fry for 20 seconds. Then add the ginger, garlic and red chilies and stir-fry for 30 seconds until fragrant.
4. Add the baby bok choy: Add the baby bok choy and stir-fry until the leaves are slightly tender but the stalks still retain some crunch.
5. Add the chicken, noodles, and sauce: Add the chicken and toss briefly to combine. Then add the noodles and pour the sauce on top. Stir-fry and mix until everything until the sauce thickens and is evenly coating everything.
6. Toss through the spring onion: Season with Thai chili powder and toss through the spring onion dark green parts. Switch off the heat.
7. To Serve: Divide evenly in bowls or on plates. Garnish with more chopped spring onion and roasted cashews (or peanuts or toasted sesame seeds). Serve immediately with chili crisp or chili oil if desired.