Microwave broccoli on high for about 5 minutes, so it's cooked about halfway but not limp. Combine soup, eggs, cheese, mayonnaise, and onion; fold together. Add broccoli last and combine. Pour into greased casserole dish and cook at 160ºC for 35-40 minutes or till a knife inserted into the middle comes out clean.
Notes: I usually double this recipe and cook in a pyrex 13X9 pan, it then needs to cook for about 50 minutes, sometimes a liitle more.
I've also used miracle whip when out of mayo and it makes no difference. The same for the onion; real onion for minced has never been a problem.
The main thing is to use a casserole dish or another low dish, if you put it in a bowl or deep dish it won't ever "set".
This is always on the table at any of my families get togethers, easy to throw together and no leftovers.