In a 9" or 10" pan, heat olive oil (or bacon fat, or whatever your favorite fat is), add a chopped onion, three small (or one large) chopped potatoes (all about 1/2" dice) and about a tablespoon of minced garlic. Add salt and pepper and sauté over medium-high heat until the potatoes are lightly browned on the outside and tender in the middle.
Add a handful of chopped mushrooms (or any other veggies in your fridge) and sauté a couple minutes more.
Meanwhile, beat six eggs with about 1/4 cup of cream, add 1/4 cup of shredded cheese (whatever kind you like), and add any herbs and spices you like. I added a pinch of herbs de Provence, a bit of nutmeg and a little more s&p. Put the pan in a 375 oven and bake for about 20-25 minutes. Then put it under the broiler until it's lightly browned. Watch it closely - it'll only take 3-4 minutes.
Then chow down.
Quick, easy and yummy. Good reheated or at room temp.