Start with your mushrooms sauté in a pan a (large enough for the omelet, it will be the same) with a teaspoon of olive oil (it will be evaporated before adding the eggs). Stir from time to time and add salt and pepper.
Beat four eggs together in a bowl and season with salt and pepper.
Once the mushrooms are cooked, pour over the eggs and add the parsley (chopped beforehand). Depending on your taste, leave more or less cooked. To me, a good french omelet is flowing but everyone’s tastes!