Better than Quiche, Spring Frittata

In life there are always those days where you look around the fridge and there are a variety of single serving vegetables, you want to cook them, but you can't simply look up a mushroom recipe or a spinach recipe, because the math involved alone would be so very complicated, and I don't even own a 1/8 tsp measuring spoon (not that I don't totally change how much I use of a spice according to my own personal taste anyway, but you know what I mean) One of those really great recipes is Quiche, I love quice, what I don't love is pie crust. I am terrible at making them, my hands are really warm I have no business touching dough (though I most certainly do) so I buy my crusts, but it's not exactly something I keep on hand, and have you ever noticed how they hide crust in the dairy section at the grocery store, usually near the puddings and jellos, in some impossible to spot location, they really don't want you remembering to pick up crust, So I left the world of quiches behind and ventured in the world frittata and eggs, something I always have on hand, usually I even have a carton of egg whites around because I can never correctly judge how much I need for fish, (sounds like I'm crazy again right, but that's a very big party recipe, so I'll get to it another day, after a really big party)
So frittata, I made this according to what I had on hand,
3 eggs
1/2 c egg whites
1/2 onion, chopped,
10 mushrooms
6 oz spinach
1 zucchini, sliced
1/4 c grated gruyere
14 c cream cheese, broken up
olive oil
salt + pepper
pepper flakes

Cook the chopped onion in a little olive oil on medium heat, until it starts to get a little color, add the mushrooms, cook til browned, add half the spinach, and cook down.
Mix eggs and whites, add salt and pepper and chili flakes, (you don't want too many bubbles upon mixing) Add cheeses.
Add the mushroom mixture and zucchini. place in an oven proof dish that has been greased with a little olive oil, I don't like to flip my frittata, it takes away from the lightness by adding the browned layer on top.
Bake at 350 for around 15 to 20 minutes, 5 minutes before it's done, top with remaining spinach, adds a layer of freshness (takes away the need to serve salad along side)
Serve warm,

I find the whites give this a little lightness, but the yolks and cheeses help keep it in the comfort food range.