Dice chicken breast into 1" cubes and season with garlic powder, white pepper, and salt.
Coat the chicken pieces with a mixture of cornflour and plain flour.
Air fry at 200°C / 400°F for 12-15 minutes, or oven bake at 200°C / 400°F for 20-25 minutes. Toss/flip halfway through cooking.
Slice the red bell pepper and white onion.
Prepare the sweet and sour sauce by combining soy sauce, rice vinegar, low sugar ketchup, pineapple juice, and brown stevia.
Mix cornstarch with water to create a slurry and add to the sauce to thicken.
Combine the cooked chicken with the sauce, sliced vegetables, diced pineapple, and green onions.
Divide into 4 meal prep containers and store for up to 5 days in the fridge.
To reheat, add contents to a microwave-safe bowl and microwave for 3-4 minutes until heated through, mix well and enjoy!
Alternatively, you can reheat in a pan.