Lightly mist a 13 by 9 inch glass or ceramic dish with vegetable oil spray.
Place the butter in a large safe dish and melt in microwave on high until melted,(50 seconds). Stir in broccoli, onions, eggs, cottage cheese, and salt. Stir in corn muffin mix until all big lumps are gone. Pour into baking dish.
Bake until light brown and springs back when pressed, about 25 minutes. Let cool slightly before serving.