Rinse the chicken breast with cold water and pat it dry with paper towels. Cut the chicken into cubes and marinate it with cornstarch and rice wine (if using). In a separate bowl, mix all the ingredients for the Sauce together and set aside.
Heat a wok or skillet over medium-high heat with 1 tablespoon of oil. Stir-fry the chicken until it turns white (it doesn't need to be fully cooked). Remove the chicken from the wok and set aside.
Add the remaining 1 tablespoon of oil to the wok or skillet. Then, add the ginger and bell pepper, stirring until you can smell the aromatic scent of the peppers. Return the chicken to the wok, then stir in the sauce. Toss and stir-fry continuously until the chicken is fully cooked and the sauce thickens. Adjust the seasoning with salt to taste.
Add the cashew nuts and stir quickly to combine. Dish out and serve immediately with steamed rice.