Start by soaking the dried glass noodles in warm water for about 20-30 minutes, or until they are soft and pliable. Once ready, drain and set aside.
In a mixing bowl, combine the chicken thighs with 1 tablespoon of reduced sodium soy sauce, 1 teaspoon of toasted sesame oil, 1 teaspoon of cornstarch, and 1/2 teaspoon of pepper. Mix well and let it marinate for about 15 minutes.
In a large skillet or wok, heat 1 tablespoon of peanut or vegetable oil over medium-high heat. Once hot, add the marinated chicken and stir-fry until it's cooked through and slightly golden, about 5-7 minutes. Remove the chicken from the pan and set aside.
In the same skillet, add a bit more oil if needed. Add the sliced onion, carrots, and cabbage. Stir-fry for about 3-4 minutes until the vegetables are tender yet still crisp.
Add the minced garlic and ginger to the pan. Stir and cook for an additional 1 minute until fragrant.
Add the cooked chicken back into the pan along with the soaked glass noodles, tomatoes, red bell pepper, and the whisked eggs. Stir everything together until well combined.
In a separate bowl, whisk together the oyster sauce, reduced sodium soy sauce, dark brown sugar, fish sauce, rice vinegar, water, molasses, dried basil, ground coriander, ground white pepper, and crushed red pepper flakes. Pour this sauce over the stir-fry and toss everything to coat evenly.
Continue to cook for another 2-3 minutes, allowing the noodles to absorb the sauce and the flavors to meld together.
Remove from heat and serve immediately, garnishing with chopped green onions and optional sliced chilies or chili sauce for extra heat. Enjoy your delicious Pad Woon Sen!