Preheat oven to 350°F and grease a large casserole dish with nonstick spray and set aside.
In a large skillet, sauté diced onions and celery in the butter until tender - still crunchy not mushy.
2 medium yellow onions, 3 celery stalks, 2 tablespoons salted butter
While the onions and celery are cooking, boil the broccoli until fork-tender and drain.
1 (16 oz) bag frozen broccoli florets
Once the onion mixture is cooked, add half of the celery and onion mixture and the soups to the cooked and drained broccoli. Mix over low heat until heated through.
1 (10.5 oz) can cream of mushroom soup, 1 (10.5 oz) can cream of chicken soup or broccoli cheddar soup
Stir in the cheese and transfer to a large casserole dish.
2 cups shredded cheddar or Colby Jack cheese
Mix remaining celery and onion mixture, stuffing, and chicken stock to make the topping. Spread over the top of the broccoli mixture.
1 cup chicken stock, 2 cups Pepperidge Farms Herb Stuffing Mix
Cover and bake for 45 to 60 minutes. The casserole should be bubbling when done. If you want the top a bit crunchy take the cover off for the last 10 to 15 minutes of baking.