This is one of those recipes that depends entirely on your own preferences.
Cooked rice. I cook a cup of dry and use whatever volume that produces. My Nanny used white rice, I use brown basmati,
Chopped broccoli. I use about the same amount as the rice, maybe a little less.
Cream of Mushroom Soup! (Yes, this is one of those recipes). I use one can of Amy’s. It’s vegetarian and doesn’t have any HFCS in it. Don’t dilute it.
CHEESE! I usually grate about a cup and a half to 2 cups of medium sharp cheddar.
Mix it all together in a big bowl, dump it into a casserole dish and bake at 325°F covered for 30 minutes to an hour. It’s already cooked. All you’re doing at this point is melting the cheese into it.