A frittata is so easy to make, good for you, and economical (make use of those leftovers!).
First, decide what's going into your frittata. This is a great way to get rid of the week's leftovers. You can use anything. Just make sure to adjust your seasonings depending upon what you're using. If it's Mexican food leftovers you're using, use spices for the frittata like chili powder and cumin that match the flavors.
If you make your own bread and have some stale or day-old sitting around, use that too!
Add some extra-virgin olive oil to the pan and heat it up.
First, I like to saute some onion and garlic.
If using bread, you can cube it and add it next or do as the Tuscans do. They soak their day-old bread in a bit of water then squeeze out the water and add it.
After your onions, bread, or leftovers are cooked through add the eggs (first you'll need to stir them in a bowl with a bit of milk). Use the best eggs you can find. Support a local farmer! Buy free-range local eggs. You'll be amazed at how much better they taste and they're also better for you (this link is to a study of free-range eggs). Plus you're supporting a local family farm.
As I like to take a shortcut whenever I can, I next put a lid on it and turn the heat down as low as it will go. (Traditionally a frittata is cooked partially on the stove then moved under the broiler to cook the rest of the way).
When the eggs are setting up, sprinkle some cheese on it.
It's ready to eat when the eggs are completely set. Just cut it in the pan and dish it out.
This one has onion, garlic, bread, and asparagus.