In a medium bowl, whisk together 1 ½ teaspoons of cornstarch, 3 tablespoons of ponzu soy sauce, garlic powder, red pepper flakes, and 2 teaspoons of oyster sauce until the cornstarch dissolves. Add the sliced chicken to the marinade, ensuring every slice is evenly coated. Cover and marinate for at least 20 minutes, ideally for 2-3 hours in the refrigerator.

In a measuring cup or small bowl, combine the remaining 1 ½ teaspoons of cornstarch, 3 tablespoons ponzu soy sauce, 2 teaspoons oyster sauce, chicken stock, minced garlic, and chili crisp. Whisk the mixture until smooth and set aside.

Heat a large wok over medium-high heat. Add 1 tablespoon of oil and toss in the zucchini and diced onions. Stir-fry for about 2 minutes, or until the zucchini and onions blister while maintaining their crispness. Transfer the vegetables to a plate and set aside.

Add the remaining tablespoon of oil to the hot wok. Add the marinated chicken slices and stir-fry for 4-5 minutes, or until the chicken is almost fully cooked. Stir frequently to prevent sticking and ensure even cooking.

Pour the prepared sauce over the chicken in the wok. Stir well to coat the chicken evenly, allowing the sauce to cook and thicken. Once thickened, return the sautéed vegetables to the wok and toss everything together. Cook for an additional 1-2 minutes until the ingredients are fully incorporated and heated through.

Remove the wok from heat and serve the stir fry warm. For a complete meal, serve over white or brown rice. Garnish with sesame seeds if desired.