Cut the chicken tenders into 1-inch chunks.
Season chicken with marinade, and set aside for 15 minutes.
Wash the celery stalks; remove and discard the foliage; dry thoroughly with paper towels.
Cut the celery stalks on a bias at 45 degrees into 1/2 inch pieces.
Heat 1/2 tbsp oil to medium hot, add ginger slices, and saute till fragrant.
Add celery and saute for 1 minute, then add sugar and salt and saute for 1 minute.
Add 1/4 cup water, cover, and cook for 3 minutes.
Transfer celery onto a plate, save the liquid, and set aside.
Add 1 1/2 oil to a clean pan and heat to medium-high.
Add chicken, gently loosen meat evenly in pan and leave to cook for 1 minute, turn chicken over, add garlic and saute for 3 minutes.
Add the oyster sauce, the reserved liquid from cooking the celery, and 1/4 cup water, stir well.
Cover and cook for 3 minutes.
Add the cooked celery, mix well.
Turn off the heat then add the cashew nuts.