Mix the eggs, parmesan, parsley, and some salt and pepper together in a bowl.
Crumple up a piece of parchment paper, dip it in water, wring it out, and then smooth it out on a sheet pan. Pour the egg mixture into the pan and bake at 355°F for 10-15 minutes.
Spread plastic wrap over the pan and flip it upside down onto the table. Let the omelet cool down a bit.
Depending on which omelet recipe you want, spread the appropriate ingredients over the omelet and roll it up afterwards. Let it sit for a few minutes before you remove the plastic and put it in the oven so that it has time for its shape to take hold.
First fry the onions in the butter. Spread the caramelized onions over the omelet roll, followed by the ham slices, and finally the cheese slices. Roll up the omelet, remove the plastic wrap, and bake for 10 minutes at 355°F.
Spread the spinach over the bottom, sprinkle grated nutmeg over it, season with a little salt and pepper, and then spread the feta cheese and then the almonds.
Spread cream cheese over the bottom, then lay the salmon on top, and finally top off with arugula.
