Line bottom and sides of casserole dish with Tater Crowns. Bake at 350°F for 10 minutes, uncovered. While the Tater Crowns are baking, brown hamburger, season to taste, and drain. Assemble soup mixture: cream of celery soup, milk, 1/2 of cheese, 1/3-1/2 can of onions, salt & pepper, and garlic powder to taste.
Add hamburger in a layer to bottom of casserole dish, then broccoli, then soup mixture. Cover with foil.
Bake at 350°F for 30-45 minutes. When casserole is heated through, remove from oven and add remaining cheese and onions on top. Bake uncovered additional 10 minutes until cheese is melted and onions are browned.