1heat oven to 350^. Butter or grease a large casserole.
Cook or steam broccoli until tender. Drain well. Combine soup, onion, eggs,cheese and mayonnaise in a large bowl.
2Place a 1/2 of the cooked broccoli in the casserole dish and then cover with 1/2 the mushroom sauce. Repeat with remaining broccoli and sauce.
Combine the dry bread crumbs with the melted butter and stir to moisten evenly. Sprinkle on top of sauce.
3Bake in oven for 30 minutes or until hot and bubbly and bread crumbs are golden brown.