Marinate the chicken by dicing boneless, skinless chicken thighs into bite-sized pieces and combining with soy sauce, teriyaki sauce, and sesame oil. Let marinate for 15 to 30 minutes.

Preheat the Blackstone griddle to medium-high heat and add vegetable oil.

Cook the marinated chicken in a single layer for 5 to 7 minutes until golden brown, then transfer to a plate.

Sauté zucchini and onion in vegetable oil for 3 to 4 minutes until tender.

Scramble the eggs in the empty space of the griddle for 2 to 3 minutes and mix with vegetables.

Add cold cooked rice and mixed vegetables, stirring for 2 to 3 minutes until heated through.

Combine the cooked chicken back with rice and vegetables, mixing thoroughly and adjusting seasoning to taste.

Transfer to a serving platter, garnish with green onions and sesame seeds, and serve.