Hold your knife at a 45-degree angle and slice the chicken against the grain into thin pieces, about ⅛-inch thick. Add the chicken to a medium bowl with the soy sauce, water, sugar, baking soda, salt, olive oil, and white pepper. Mix well, then add the starch and toss again to coat.

Finely mince the garlic and julienne the ginger. Slice the scallions into small rounds, keeping the white and green parts separate. Slice the shiitake mushrooms into strips.

Trim about ½ inch from the bottom of the napa cabbage and remove any bruised or dirty outer leaves. Quarter the cabbage and cut out the hard core at the bottom.

Separate the thicker stems from the leafy parts. Cut the stems into smaller bite-size pieces and the leafy parts into larger pieces. Rinse and drain well, keeping the stems and leaves separate.

In a small bowl, combine the sauce ingredients from soy sauce to Chinese rice wine, if using. Stir well and set aside.

Preheat a large sauté pan or wok over medium heat until it feels quite warm. Add 1 tbsp oil and swirl it around the pan.

Add the chicken, turn the heat up to medium-high, and quickly spread the pieces into a single layer. Pan-fry without moving them until the bottom turns golden brown, about 2 to 3 minutes. Flip and sear the other side for 1 to 2 minutes, or until the chicken is cooked through and golden on the outside.

Transfer the chicken to a plate and set aside.

Use the same pan and add 1 tbsp oil. Add the garlic, ginger, and white scallion parts with a pinch of salt. Sauté over medium heat until fragrant, about 15 seconds.

Turn the heat up to medium-high. Add the napa cabbage stems and season with 2 pinches of salt. Stir-fry until the stems begin to turn tender, about 2 minutes. If the pan feels dry, add another ½ tbsp oil.

Add the leafy parts of the cabbage, shiitake mushrooms, and ½ tbsp chicken broth to lightly deglaze the pan. Toss everything together, then lower the heat to medium and cover with a lid.

Cook until the cabbage wilts slightly but still holds its shape, about 3 minutes.

Uncover and turn the heat back up to medium-high. Return the chicken to the pan. Stir the sauce again, then pour it into the skillet.

Toss everything together for about 1 minute, until the sauce lightly coats the chicken and vegetables. Turn off the heat.

Transfer to a large serving plate. Garnish with the green scallion parts and drizzle with toasted sesame oil. Serve hot or at room temperature.