1 cup mayonnaise
1 cup condensed cream of mushroom soup
2 (10 ounce) packages frozen chopped broccoli, thawed
1 cup shredded Cheddar cheese
1 onion, chopped
1/2 cup butter, cut into pieces
3/4 cup crushed buttery round crackers (such as Ritz(R))
Preheat an oven to 325 degrees F (165 degrees C).
Beat the eggs in a mixing bowl; whisk in the mayonnaise, cream of mushroom soup, broccoli, Cheddar cheese, onion, and butter. Spoon into a 2 quart casserole dish; sprinkle with the crushed crackers.
Bake in the preheated oven until hot and bubbly, 30 to 40 minutes.