In a bowl, toss the chicken meat with the soy sauce and cornstarch.
In a separate bowl, whisk together the ingredients for the sweet and sour sauce.
Heat a wok or saute pan over high heat. Swirl in just 1 tablespoon of the cooking oil. When hot, add in the marinated chicken. Spread chicken out all over the surface of wok in single layer. Let cook for 2 minutes, undisturbed, until browned. Flip chicken pieces and brown the other side, about 1 minute. Chicken should be browned but still uncooked in the middle. Remove chicken from wok and set aside.
Keep the wok on stove and turn the heat to medium-high. Swirl in the remaining cooking oil. When hot, add the onions and stir fry for 1 minute. Add in the cherries, red and yellow bell peppers. Stir fry for 2 minutes, until the bell peppers are cooked, but still colorful and crunchy.
Add the partially cooked chicken back into the wok and pour in the sweet and sour sauce. Bring to a simmer and cook an additional minute, or until the chicken is fully cooked through. Careful not to overcook the chicken!