Start by shredding the frozen chicken breast using the large holes on the grater and transfer to a large bowl.
Add the processed cheese, the grated mozzarella, the red onion chopped into small cubes and the grated potatoes.
Season everything with the salt, a pinch of black pepper, the oregano and mix everything very well until combined.
In a large skillet over low heat add a drizzle of vegetable oil and spread it with a brush.
Then add the mixture we prepared using a spoon and spread it evenly.
Cover the skillet and let it fry for 10 minutes.
After this time has passed, flip the omelet using a plate.
Add +100g of grated mozzarella.
Cover the skillet again and let it fry for another 5 minutes.
Serve.