To prepare the chicken: Make shallow cuts across each chicken thigh about 1 inch apart without cutting all the way through. Season both sides with the salt and five-spice powder, then lightly coat both sides with the cornstarch.
To pan-fry the chicken: In a large pan over medium-high heat, add the cooking oil. Add the chicken and pan-fry for about 6 minutes, until golden brown. Flip and cook for another 6 minutes, until golden brown. Remove the chicken and set aside.
To make the five-spice sauce: In the same pan over medium heat, add the chicken stock, soy sauce, dark soy sauce, oyster sauce, Shaoxing wine, honey, five-spice powder, garlic, and ginger. Stir well and bring to a simmer.
To finish the five-spice chicken: Return the chicken to the pan and coat it with the sauce for about 2 minutes, until the sauce becomes rich and glossy. Cook until the chicken reaches an internal temperature of at least 165°F (74°C).
To slice and serve: Transfer the chicken to a cutting board and slice into bite-sized pieces. Drizzle the remaining sauce over the chicken and serve with steamed rice and your favorite vegetables.