Slice the chicken against the grain into thin strips around 2 inches long and around ⅛ inch thick. Place the chicken into a large bowl.

Add the cornstarch and garlic powder to the chicken and toss to coat. Let sit in the cornstarch for 5 minutes.

Heat the air fryer to 400 degrees.

Add the chicken to the air fryer basket, spreading it out to be mostly in a single layer, and spritz liberally with oil.

Air fry for 8 minutes, stirring the chicken every couple of minutes. Spritz again with oil if you notice any dry spots of cornstarch.

While the chicken is cooking, heat the oil in a large deep skillet on the stove. Add the garlic and ginger and cook in the oil for 30-60 seconds, until fragrant.

Add the soy sauce, water, and brown sugar to the skillet and stir well.

Bring to a boil and cook for 6-7 minutes, stirring occasionally, until sauce has thickened.

Carefully add the cooked chicken to the sauce and continue cooking for 1-2 minutes, tossing the chicken in the sauce to coat well.

Sprinkle chopped green onions over the top before serving.