Season both sides of chicken breast with salt and pepper. (*footnote 1)

Whisk all the sauce ingredients in a small bowl.

Combine cornstarch with 1 tablespoon water. Mix well and set aside.

Heat a large large skillet over medium high heat until hot. Add 1 tablespoon oil and swirl the pan to coat the skillet with oil. When the oil is just about to smoke it’s ready to cook. Add chicken and cook without moving until the bottom side turns golden brown, 2 to 4 minutes. Flip and cook the other side until browned, 1 to 2 minutes. Turn to medium low heat and cover. Let steam for 2 to 4 minutes until the juice runs clear if poking with a skewer. Check once in between and flip chicken if the bottom side turns too brown. Transfer to a plate immediately. Remove the skillet from stove once done cooking to let cool off for a bit.

Cover chicken loosely with aluminum foil. Tear the top of the foil into a 2-inch long gap to let steam out, so the chicken will remain crispy.

To cook the sauce, add the remaining 1 tablespoon oil and garlic into the same skillet and cook over medium heat until fragrant. Pour Shaoxing wine (or dry sherry) to deglaze the pan. Quickly use a spatula to release any brown bits stuck to the pan.

Stir the sauce again to mix well, pour into the pan. Let cook until it reduces to half.

Now return any dripped chicken juices from the plate with cooked chicken breast by tilting it with one hand while the other hand holds the aluminum foil.

Add butter. Keep stirring until the butter melts.

Stir the cornstarch slurry again to mix well. Pour into the pan and stir until the sauce thickens.

Pour the sauce over the chicken, sprinkle with green onion, and serve immediately.

If you need to serve the dish later, keep the sauce on stove with lowest heat. If the sauce starts to get to thick, add a bit water or chicken stock to thin it out.

Serve over brown rice with blanched or roasted vegetables.