Place the chicken in a resealable plastic container.
In a large measuring cup, whisk together the soy sauce, brown sugar, 2 tbsp of water, vinegar, honey, garlic, sesame oil, ginger, and pepper until the sugar is dissolved.
Pour half of the marinade over the chicken, reserving the remaining marinade.
Refrigerate for at least 30 minutes.
In a large skillet over medium-high heat, heat the oil.
Add the chicken and cook, until cooked through, about 3 to 5 minutes.
Reduce the heat to medium.
In a small bowl, whisk 2 tablespoons of water with the cornstarch.
Pour the reserved marinade into the skillet over the cooked chicken.
Cook, until the sauce thickens and coats the chicken evenly, 3 to 5 minutes.
Garnish with the green onion and sesame seeds.
Serve hot with broccoli and rice, if you like.