In a small saucepan over medium heat, combine soy sauce, brown sugar, garlic, ginger, and rice vinegar. Bring to a simmer.

Mix cornstarch with 2 tablespoons water and stir into the sauce. Cook until thickened, about 2–3 minutes.

Cut chicken thighs into bite-sized pieces and cook in a skillet over medium-high heat until fully cooked and golden brown.

Pour the teriyaki sauce over the chicken and stir to coat evenly.

Steam the broccoli and carrots until tender-crisp.

In a serving bowl, place a scoop of cooked rice, add the teriyaki chicken, then top with steamed vegetables.

Garnish with sesame seeds and chopped green onions. Serve warm.