In a bowl, mix the chicken with baking soda until the chicken is coated. Let the chicken marinate for 15 minutes.
Wash off the baking soda and rinse the chicken several times.
For the sauce: In a medium bowl, mix all the sauce ingredients and stir well.
Prepare a pan, add oil, and then sauté garlic and onion until fragrant.
Add green bell pepper, and sliced mushrooms. Stir well.
Add the chicken to the pan and cook for 1-2 minutes. Pour the sauce mixture into the pan. Stir well.
Lastly, add thinly sliced green onions.
It's now ready to be served.