In a medium bowl, combine 2 tablespoons of soy sauce, 1 teaspoon sesame oil, rice wine vinegar, and minced garlic. Add the cubed chicken and toss to coat. Let it marinate for at least 10 minutes.

Heat a large pan or griddle over medium heat. Add 1 teaspoon of sesame oil to the pan. Once hot, cook the marinated chicken, searing on all sides until fully cooked, about 5-7 minutes. Push the chicken to the side of the pan.

In the same pan, add the frozen vegetables. Stir-fry them for 3-4 minutes until they are tender but still vibrant in color.

Break up any clumps in the day-old rice and add it to the pan with the veggies. Pour in 1 tablespoon of soy sauce and toss everything together. Stir-fry for 2-3 minutes, allowing the rice to absorb the soy sauce.

Push the rice and vegetables to one side of the pan. Pour the beaten eggs into the empty space and scramble them. Once fully cooked, mix the eggs into the rice and vegetable mixture.

Add the cooked chicken back into the pan. Stir everything together and cook for another minute to heat through. Adjust seasoning by adding more soy sauce or a dash of sesame oil if needed.

Remove the pan from heat. Garnish with chopped green onions and sesame seeds. Serve hot and enjoy!