I do it differently.
Chop half a small cooking onion or 1/4 of a spanish onion.
Chop 4 mushrooms, not too finely.
add a dab butter and oil to a non-stick frying pan - turn the heat up to medium.
Add the onions & mushrooms to the pan and fry until limp. Transfer to a plate.
Take out the extra fat.
Break two eggs in a cereal bowl, add a tablespoon of cold water and some tabasco, celery seed, worcester and salt. -- whip it good with a fork.
Bring the pan back to the burner but turn the heat down to 3. Make sure the pan isn't hot. Pour the beaten eggs into the pan.
The eggs will start to cook immediately - this is good but you have to continually scrape the cooked parts from the bottom of the pan with a flipper thingy.
When the egg mixture is almost congealing, form a 4 inch diameter circle in the middle of the frying pan. Put the onion & mushrooms on top. Put some grated cheese on top of that.
Cover the pan and put the timer on for 5 minutes. Low heat.
When it's done, (eggs are cooked but not dry and the cheese is all melted), slide the omelet off the pan onto the centre of a plate your grandmother bequeathed to you or one of those melamine camping plates but NOT a Corelle product.
A side of toast, some cucumber slices and a glass of wine would be nice. You can sprinkle some sesame seeds on top. Light a candle and wish you had made two.