In a medium sized bowl, combine chicken thighs, hoisin sauce, mustard, maple syrup, black pepper, salt, garlic powder, and onion powder ensuring that the chicken is coated.
In a heavy set pan turn heat to a medium high. Add in oil, wait till it gets hot, then place the chicken skin side down to get a nice sear. Once the sear has been created flip over, lower heat to medium and cover, cook for 10 minutes.
Once it has cooked for 10 minutes take the lid off an add in sliced bok choy to let it marinate and cook with the chicken for an additional 10 or until the chicken is cooked.