Place the raw diced chicken into a large bowl and toss with flour until well coated.
In a large frying pan, heat sesame oil over medium heat. Add the diced chicken and cook until lightly golden on the edges and no longer pink, about 10 minutes. You may wish to add a splash of water to the pan if the flour coating starts to stick to the pan. Meanwhile, whisk together the sauce mixture in a separate bowl until there are no lumps.
Once the chicken is cooked, remove it from the pan and set it off to the side in a separate bowl.
Drain any liquid from the pan and pour the sauce mixture into the same pan you cooked the chicken in.
Turn the heat up to high and bring the sauce mixture to a boil. Once boiling, reduce heat to medium and simmer for approximately 15 minutes, stirring every minute or so until it starts to thicken.
Add the chicken back to the pan and mix to combine with sauce, cooking for another 2 minutes. Let it cool for about 5 minutes to allow the sauce to further thicken.
Serve warm over rice or quinoa topped with sliced green onion and sesame seeds.