In a large frying pan or wok, heat oil.
Cook celery 2 minutes or so.
Add oyster mushrooms, corn and garlic.
Stir fry 1 minute or so.
Fold in chicken broth.
Continue cooking 2 minutes, stirring constantly.
In a small bowl, dilute cornstarch in cold water.
Fold into mixture in pan.
Season with salt and pepper, mixing well.
Continue cooking until sauce thickens.