Sauté sweet onion on medium low heat until almost transparent, add thinly sliced garlic and continue sautéing until just starting to brown, then add squash, zucchini, bell pepper and toss until starting to get tender.
Separately sauté or microwave broccoli briefly, cover for a couple of minutes. You want the broccoli to start to get tender.
Beat eggs, add cream, salt, pepper, nutmeg.
Butter a deep dish pie pan or any shallow pan that holds about a quart of liquid. A casserole dish will work also. Spread veggies then add the egg mixture, then the grated cheese, tossed with the green onion. Bake at 425 for 10 minutes, then decrease heat to about 325 for another 15 minutes or so. It should brown lightly on top and appear “set” when you tip the pan at an angle.