Add 1½ cups of uncooked rice to rice cooker. Cook according to package instructions. You can also cook on the stove.
Preheat the oven to 350°F.
Cut the chicken into small bite-size pieces.
Add raw chicken to a bowl along with cornstarch (or arrowroot powder) and toss together. Set aside.
In a small bowl combine the sauce ingredients: coconut sugar, tomato paste, apple cider vinegar, soy sauce and garlic powder. Mix together. Set aside.
Heat a frying pan (or oven-safe pot) with a bit of cooking oil on the stove. Once pan is hot, sear the chicken for only 30 seconds. This is to help seal flavors in.
Remove from heat. Pour the sauce over the chicken and mix together. Transfer to an oven-safe dish if needed. Bake for 35-45 minutes, or until chicken is fully cooked. Stir the chicken halfway through baking.
Add cooked rice to a plate and top with the sweet and sour chicken. Optional toppings include green onion and sesame seeds.