This was an easy and delicious meal. I worried that the celery and onions needed to be sauteed first, but I put them in chopped and raw. I added 2 cans of tuna (instead of one). I used crushed Corn Flakes without any butter. I baked at 350 for 30 minutes. Excellent! The celery and onions were a bit crunchy, but very good. My husband suggested that I should make this on a regular basis. He wants to take the leftovers for lunch the next day.