I say roughly because I'm not claiming to be a great cook, but do remember her instructions to make an omelet in about 30 seconds so you get the pan to near smoking before you pour he eggs in (add a teaspoon of water to strengthen the egg walls etc.)

No, you don't need a filling to call it an omelet, although I certainly put stuff in from time to time by folding it over. That's the final word, an omelet can be just eggs + teaspoon of water cooked on smoking butter.
[Post edited by `lag at 03/04/2016 10:47AM]