Is there any difference, besides the look, between a rolled and folded omelet? Does it change the texture? Or is one better for different ingredients? I’ve never made a rolled omelet but am thinking about trying it.
To me, there’s no difference. You make the omelet and either roll or fold it. However, to some people, a folded omelet has a firmer texture than a classic French rolled omelet. As for those absurd folding skillets, usually Teflon, which supposedly make folded omelets easy? Those don’t make omelets. All they allow you to make is two semi-circles of flat frittata-like egg which are laid one of top of another, layers which are usually tough to boot.
Auguste Escoffier says succinctly in The Escoffier Cook Book, “The procedure for omelets is at once very simple and very difficult, for tastes differ considerably in respect to their preparation. Some like them well done, others insist upon their being just done enough, while there are yet others who only enjoy them when they are almost liquid.”
You can count me out of the “almost liquid” category, but I do like my omelets creamier (the French term is baveuse) than many Americans. When one of my clients was running around about to leave the house without having eaten, a bad habit of hers, I volunteered to make her an omelet, knowing it would take about the same amount of time as a piece of toast. Well, you’d have thought I was trying to poison her; she took a bite and almost choked. “This is raw!” she gasped. It wasn’t, of course, but I scooped it back into the pan and turned it into something more resembling hard-cooked scrambled eggs, which was more to her taste. Chacun à son gout, as the expression goes.
Here’s Escoffier again, “Nevertheless, the following conditions apply to all—namely, that there should be complete incorporation of the egg-molecules; that the whole mass should be smooth and soft; and that it should be borne in mind that an omelet is really scrambled eggs enclosed in a coating of coagulated egg.”
So texture is a matter of preference. As for fillings, if they contain protein or water, they should be added after the omelet is cooked; if they should touch the pan, the mixture will stick and your omelet will be neither roll nor fold. Pre-sauté or pre-cook fillings such as vegetables or meats. Have them warm or at least room temperature; add them and/or cheeses before the omelet is folded.
The only things which should be added to the egg mixture itself before cooking are chopped herbs or diced potatoes, croutons, or other foods which have been previously cooked; and they should be cut up fairly small or you risk tearing the outer envelope of cooked egg.