Prepare the sauce. Cut chicken into small pieces. Diced or in strips. Head 1-2 cups peanut or other cooking oil in your wok. Place corn starch in a small bowl and being to dust chicken pieces, shaking off excess. Fry in hot oil in small batches until crispy and golden, about 2-3 minutes; drain. Heat 1 tbsp of oil in wok and stir-fry onion and celery about 1 minute. Add sauce mixture to wok along with chicken and stir to coat everything.
Mix together ingredients in a small bowl. You can prepare the sauce in advance of your recipe and store in the refrigerator.