Preheat oven to 220C/425F. Toss the vegetables in olive oil, salt and pepper and place them on a baking tray. Roast for 20 minutes.
To make the teriyaki chicken, marinate the chicken in garlic paste for 15 minutes.
Add oil to a non stick pan, and add the chicken pieces to it. Cook the chicken pieces for 8-10 minutes.
While the chicken is cooking, stir together soy sauce, chopped ginger garlic, honey, vinegar, chilli flakes, cornstarch and 1 1/2 cups water in a bowl.
Add the sauce to the pan and bring it to a quick boil while stirring continuously. Once the sauce starts thickening up, lower the flame and simmer for 2-3 minutes. Switch off the flame and set aside to cool slightly.
Let everything come to room temperature before assembling the meal prep boxes. To assemble, divide the rice, roast vegetables and teriyaki chicken in each box. Sprinkle with sesame seeds, shut the lid and refrigerate. You can store these for up to 5 days.