In a small bowl, whisk together soy sauce, honey, rice vinegar, garlic, ginger, and cornstarch until smooth and set aside.
Heat vegetable oil in a large skillet over medium-high heat and add the chicken pieces, cooking for 6-8 minutes until golden brown and cooked through.
Add broccoli florets to the skillet and cook for 3-4 minutes until crisp-tender.
Pour the teriyaki sauce over the chicken and broccoli, stirring constantly for 2-3 minutes until the sauce thickens and coats everything.
Divide rice among four bowls, top with teriyaki chicken and broccoli, and garnish with sesame seeds and green onions before serving.