Ale a cornstarch slurry to add on at the end. 1 tablespoon of cornstarch mixed with a tablespoon of water.

Hi!

When it comes to thickening the sauce, it’s all about giving it enough time to cook and reduce; typically, after about 5 minutes of simmering, you should notice it starting to thicken up due to the evaporation of the liquids. If the sauce seems too thin, letting it simmer a bit longer can do the trick without needing extra cornstarch.
As for the brown color, it primarily comes from the initial browning of the chicken pieces in a single layer – using a skillet that’s large enough to fit all of them without crowding is important. If it’s too small, the chicken will steam, release its juices into the pan, and create more liquid. This browning stage not only adds depth to the flavor but also contributes to the color of the dish. Following that, adding bourbon, soy sauce, and brown sugar enhances the color further.

Using a wok could influence the cooking slightly due to its shape and how heat is distributed, but it is still possible to achieve a thickened sauce and the desired color with a large enough skillet.