A pan-sized, unfolded Italian omelet in which all the ingredients cook right in the omelet. You can flavor a frittata with any combination of cooked foods you like – vegetables, grains, meat, poultry, fish, seafood or cheese. Start cooking the egg and filling mixture on top of the range until it’s almost set. Then, you can finish cooking the top of the frittata by putting the pan under the broiler or in the oven. Or you can flip the frittata out of the pan upside down onto a plate and then slide it back into the pan to cook the other side. The easiest way is simply to remove the pan from the heat, cover it and let steam finish the cooking.
– See Tortilla