In a saucepan mix the stock, soy sauce, mirin, anise, sesame oil, honey, ginger, garlic, onion, and pepper together and bring to a boil. Simmer to meld flavors about 5-10 minutes.
Taste sauce and adjust ginger, garlic, honey, or soy sauce according to preference (some like a sweeter or saltier sauce).
Disolve cornstarch in a small amount of water, then add cornstarch mixture to the sauce. Simmer until the consistency is thick. Remove star anise and onion from the sauce, then set aside.
Salt and pepper the chicken thighs on both sides. In a skillet, add the sesame or coconut oil and cook chicken thighs over medium heat until lightly browned on each side, about 3-4 minutes each side.
Once cooked, slice each chicken thigh into thirds. Serve chicken over vegetables or rice and pour sauce over the top.
For the Vegetables:
Heat oil in a large skillet or wok, add ginger and cook until fragrant. Add prepared vegetables, and cook until crisp-tender. Salt and pepper to taste and reserve in warm oven until ready to serve.
Notes
Although Teriyaki is traditionally not a spicy dish, a few red pepper flakes can be a great addition to the sauce to add a little kick.