Creamy Broccoli Casserole

Creamy Broccoli Casserole 5 T. butter 1 medium onion, chopped 1 rib celery, diced 1 medium carrot, grated 1 clove garlic, minced (2) 12 oz. bags frozen chopped broccoli, thawed 10.5 oz. can cream of chicken and mushroom soup (the combined soup, not two separate soups) 1 large egg 1/3 C. mayo 1/2 tsp. my house seasoning (equal parts garlic powder, onion powder and pepper...combine and store in an airtight container) 1/2 tsp. salt 4 oz. pkt. vevetta cheese sauce 1 C. shredded cheddar cheese 1 sleeve ritz crackers, crushed Melt 4 T. butter in a skillet over med. high heat. Add the onion, celery, carrots and both bags of broccoli. Cook, stirring often for 6 minutes. Meanwhile, in a mixing bowl whisk together the soup, egg, mayo and seasonings. Add the broccoli mixture to the bowl and combine well. Stir in the velvetta cheese sauce. Pour into a 3 quart baking dish and top with the shredded cheese and half the crackers. Bake, loosely covered with tinfoil, in a 375 degree oven for 30 minutes. Melt the remaining tablespoon of butter and mix with the remaining crackers. Uncover the casserole, top with the remaining crackers and return, uncovered, to the oven for 10 minutes.