Bring a pot of water to boil and cook rice according to instructions.
In small bowl, whisk together light brown sugar, soy sauce, chicken stock, rice wine vinegar, peanut butter, sesame oil, ginger, ¼ cup water and 1 tablespoon cornstarch and set aside.
Beat egg in mixing bowl. Add chicken cubes with granulated sugar, salt and pepper. Coat chicken with ⅓ cup cornstarch.
Heat 2 tablespoon of the oil in a wok or cast iron skillet over medium-high heat until shimmering. Add half the chicken to skillet and cook for 3-4 minutes per side, until lightly browned. Add 1 tablespoon oil and repeat with remaining chicken. Remove and set aside.
Add garlic, green onions and dried chilis and cook for about 1 minute.
Return chicken to skillet and add sauce. Cook for a couple of minutes or until the sauce starts to bubble and thicken.
Sprinkle the chicken with some green onions and sesame seeds and serve over rice.
Notes
You can replace the chicken breasts with chicken thighs.
You control the amount of heat by the number of dried chilis you add.
If you don't have dried chilis, replace with ½ teaspoon crushed red pepper flakes.
Add 1 teaspoon of orange zest to brighten the dish up.
You know the chicken is cooked when it reaches 165°F with an instant-read thermometer or if you cut into the chicken and the juices run clear and there is no pink. Honestly, I always just cut the chicken to see when it is done. If it isn’t just cook slightly longer.