Heat olive oil in a 12-inch non-stick skillet over medium-high heat.
Add in chicken and let brown on bottom about 3 - 4 minutes then flip and continue to cook until center registers about 160 degrees, about 3 minutes longer.
While chicken is cooking, in a small mixing bowl (or liquid measuring cup) whisk together soy sauce, water, honey, brown sugar, rice vinegar, sesame oil, ginger, garlic and cornstarch.
Stir the sauce in with the cooked chicken and continue to cook and toss until sauce has thickened, about 30 - 60 seconds longer.
Serve warm garnished with green onions and sesame seeds if desired.