Preheat oil in a nonstick pan or skillet over medium heat. Whisk together corn starch, salt, 1 teaspoon garlic powder, and pepper.
Add corn starch mixture and chicken pieces to a large zip lock bag. Seal and shake to coat chicken.
Add coated chicken pieces to pan. Saute 1-2 minutes until browned. (It chicken will still be raw in the middle at this point, that's okay)
In a bowl combine all sauce ingredients and whisk to combine. Add half to the crockpot along with chicken pieces. Cook on low for 4 hours.
Immediately before serving, Add remaining sauce to the crockpot and stir gently. Serve with rice.