What's there to say about omelets? Well, for one, that Japanese-style omelets are rolled up as opposed to flat. There are special square pans made just for cooking these omelets, but you can use a regular frying pan. The directions here will work for both.
Mix your eggs and whatever else you want to put in the omelet. It's best if the "fillings" aren't too chunky. Pour in a thin layer on the bottom of the pan and cook normally. If you end up with eggs left over after pouring a thin layer, that's fine. When it's cooked roll it toward yourself, a third at a time, so you end up with a roll of omelet on the side closest to you. (This is why you don't want big chunky fillings - those can make it difficult to roll.) If you have more
eggs, pour them in, lifting the cooked omelet to let some in under there. Cook the next bit, then roll the first part over it. Bingo, a rolled omelet!
As usual, use any fillings you like. My personal favorite is mushrooms and a little cheddar cheese.
A fun variation on this is bacon & egg omelet.
Cook several pieces of bacon, then trim them to the
width of your omelet pan if they are longer than it
is wide. After you pour the first batch of egg, and
while it's still liquid, place a strip of bacon on the
side you will roll up. Roll the omelet around the bacon.
When you pour the next batch, put the bacon just after
the roll of omelet, so that when you roll it it'll go
over the bacon on the first turn. Repeat the second
step as many times as you want, until you have a rolled
omelet with strips of bacon inside.
Another fun variation is
the "rainbow rolled omelet."
Start out with plain, regular eggs. Pour the first
layer, then add a drop of food coloring to the unused
eggs and mix. That'll shade the eggs just slightly.
Pour the second layer, then add another drop of the
same color. Repeat until you run out of eggs. You'll
end up with an omelet that shades from yellow-white
in the center to a vivid color on the outside. Cut in
cross sections, this looks very pretty (and possibly
startling) in a lunch box!