This is what I make for breakfast most days of the week.
Crispy Inside-Out Omelet
sausage (or other fillings of preference)
Scatter a handful of shredded cheese over the bottom of a large non-stick pan. You want enough to cover the bottom. Turn the burner on to about 4 (a bit less than medium).
Cut up your filling and distribute it uniformly over the top of the cheese. I typically use two links of breakfast sausage (previously cooked) sliced into little rounds. Let it sit undisturbed until the cheese has begun to melt and bubble. You want it to melt evenly, so keep an eye on it and see if you need to tweak the pan's position on the burner as it starts to melt.
Meanwhile, crack two eggs into a small bowl. Add a pinch of kosher salt and a long splash of heavy cream. (Probably a couple tablespoons?) Whisk with a fork until thoroughly blended.
When the cheese is bubbling away, pour the egg mixture into the middle of the pan and let it spread out to cover the cheese. You may need to swirl the pan a little to cover any bare spots, but you don't want to be too vigorous or the eggs will go up the sides of the pan and give you a lot of thin film along the edges of your omelet.
Let it sit until the eggs are set, then use a spatula to fold the omelet in half. Slide the spatula under the middle of the omelet, turn it sideways, and transfer the omelet onto a plate. If you do it right, you can get it to form a sort of tent shape, which looks neat and will help it cool off to edible temperature more quickly. (And also makes it fit on the plate better if your plates are smaller than your pan.)
The outside of the omelet should be a rich orange-brown color with a gentle crunch. Toasting the cheese on the outside enhances its flavor, plus it greases the pan for you.
It's a little trickier if you're using something big and flat instead of small and chunky for your filling, like slices of lunchmeat. If you put a slice of lunchmeat between the cheese and the eggs, it may keep them from bonding and cause to things slide apart on your plate, but if you put it on top of the eggs, it slows their cooking and makes it harder to judge when they're done, so you're more likely to get either detachable filling or burnt cheese. You just have to do your best and remember to get more sausage next time you go shopping.
Salsa makes a nice filling, but it's prone to the same problems. Instead, you can beat it into the eggs in place of the cream. Just beware the giant blup of thixotropic flow dropping way too much into the bowl.