Awesome Broccoli-Cheese Casserole

Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C). Butter a 9x13-inch baking dish.

Whisk condensed soup, mayonnaise, egg, and onion together in a medium mixing bowl until combined.

Place frozen broccoli florets into a very large mixing bowl and break it up if necessary; add soup mixture and mix well to coat. Sprinkle with cheese and mix well; spread mixture into the prepared baking dish. Season with salt, pepper, and paprika.