Eggs
Start by cutting the potatoes into thin slices using a vegetable peeler.
In a large skillet, add the butter and stir until it completely melts.
Add the medium onion chopped into thin strips, the mushrooms chopped into smaller pieces and the potatoes we cut earlier.
Season everything with the salt, a pinch of black pepper and sauté until wilted.
Next, pass everything through a colander, press well and drain for 5 minutes.
In a medium bowl, add the eggs, a pinch of salt, a pinch of black pepper and mix very well.
Add the sautéed ingredients we prepared earlier and mix until combined.
In a large skillet over medium to low heat, add the unsalted butter and stir until it melts.
Add the mixture we prepared and spread it out evenly.
Cover the skillet and let everything fry for 5 minutes.
After this time has passed, turn the omelet over and add the slices of mozzarella cheese.
Cover the skillet again and let it fry for another 3 minutes.
Serve.