Cicely, where did you have this appetizer? A friend of mine makes a dish like this, but I don't think it's called Jade Celery. She takes celery, removes the string parts, slices the ribs into sections about 1/4-1/2 inch wide and about 2 inches long. Then she blanches them in salted water, tosses them quickly in a concotion of garlic sauce, toasted sesame oil, and Sriracha, then chills before serving. Is this what you are looking for?