In a bowl, toss chicken cubes with cornstarch until evenly coated.
In a separate small bowl, whisk together orange juice, orange zest, soy sauce, honey, rice vinegar, ginger, garlic, and red pepper flakes.
Heat olive oil in a large non-stick skillet over medium-high heat.
Add the chicken to the skillet in a single layer and cook for 6 minutes, turning occasionally until golden brown and cooked through.
Pour the sauce mixture over the chicken in the skillet.
Simmer for 3 minutes, stirring constantly, until the sauce thickens and glaze coats the chicken thoroughly.
Remove from heat and garnish with sliced green onions and sesame seeds.