Cut the chicken thigh into 1-inch pieces and place into a medium bowl. Add the white pepper, salt, canola oil, sesame oil, and cornstarch, mix well, and marinate for at least 10 minutes, up to 30 minutes.
In a small bowl, add the soy sauce, hoisin sauce, white pepper, sugar, dashi powder, water, and cornstarch. Mix until well combined and set aside.
Chop your vegetables while the chicken marinates.
Put water into a medium pot and bring water to a boil. Add the zucchini and blanch for 10 to 20 seconds. Drain zucchini in a colander and set aside.
In the 5-quart stainless steel saute pan, heat the ¼ cup of canola oil until it just starts to smoke. Carefully drop the chicken into the oil and cook for 2 to3 minutes. Don’t touch the chicken for the first minute, then stir constantly for the remaining time. Remove chicken and set aside on a plate or bowl.
Add the mushrooms, garlic, and ginger to the pan and cook for 2 minutes, stirring frequently so the garlic and ginger don’t burn.
Add the chicken, zucchini, and sauce to the pan. Mix well to combine for about 1 to 2 minutes or until the sauce is thick. Serve immediately.