*Microwave celery and broccoli on high for 5 minutes. (When I use frozen broccoli, I microwave it for 8 minutes – I like it mushy.)
In 1-qt saucepan over high heat, heat 1 can of evaporated milk and butter to scalding. In a large bowl, pour hot milk mixture over stuffing, toss to mix well. Pat 1/2 of the stuffing mixture into a buttered 9x13 baking dish.
In medium bowl, stir soup, 1 can evaporated milk, regular milk, chicken, 1 cup of cheese, celery, broccoli, thyme, and garlic powder until well mixed. Spoon evenly over stuffing mixture in baking dish. Top with remaining stuffing mixture.
Cover with foil, bake at 350 for 45 minutes, or until hot. Sprinkle with remaining cheese. Bake uncovered until cheese is melted.