In a saucepan, whisk soy sauce, water, brown sugar, honey, garlic, ginger, and vinegar. Bring to a light boil.
Mix cornstarch with water, add to sauce, and cook until thickened. Set aside.
Brush chicken with olive oil and season with black pepper.
Grill chicken over medium-high heat until fully cooked, then rest and cube.
Heat remaining oil in a pan and sauté zucchini, carrots, and broccoli until crisp-tender.
Assemble Teriyaki Chicken Rice Bowls by layering rice, chicken, and vegetables. Drizzle with sauce and garnish with sesame seeds.