Crunchy Hot Chicken Bake

I wish I had a photo of this dish! Just one look at it and my mouth starts to water.

So when I find time in my menu schedule to make this again, I will post a picture of it next to the recipe. It is so good you'll want to make this dish at least 2 time a month if not more. *I substitute Fat Free soup & light mayo*

6 TBSP. Margarine, divided
1/2 C. diced celery
1/2 C. diced Onion
4 oz. can sliced mushrooms, drained
4 C. cooked chicken, diced
1 C. Mayo
1 (10 3/4 oz) can Cream of Celery Soup
1 tsp.Pepper
2 C. French's Fried Onion's

Melt 4 TBSP of Margarine in skillet, add celery, onion. Cook until tender, spoon into a 13x9 pan. In bowl add chicken, mayo,soup, melted 2 TBSP margarine. Pour over vegetables in pan. Bake @ 350 for 25 minutes. Take out top with the fried Onions, return to bake for 8 more minutes. Serve with hot bread.