In a mixing bowl, combine the diced chicken thighs, minced garlic, grated ginger, and half of the teriyaki sauce. Allow it to marinate for at least 30 minutes (or overnight in the refrigerator for deeper flavor).
In a large skillet, heat both olive oil and sesame oil over medium-high heat. Add the marinated chicken to the pan and cook for about 6-8 minutes, or until browned and cooked through.
In the same skillet, add broccoli, bell peppers, and snap peas. Stir-fry the vegetables for about 5-7 minutes or until they are tender-crisp. Pour in the remaining teriyaki sauce and cook for an additional 2 minutes, coating the vegetables and chicken.
Divide the cooked brown rice evenly among meal prep containers. Top each with an equal portion of the teriyaki chicken and vegetables.
Sprinkle sesame seeds and sliced green onions on top of each bowl for added flavor and visual appeal.
Allow the meal prep bowls to cool before sealing them with lids. Store them in the refrigerator for up to 4 days.