Start by tying the chicken breast to a lid using pieces of string.
In a large skillet, over medium to low heat, add the water and bring it to a boil.
Add the chicken we tied to the lid and let it cook for 5 minutes.
After this time has passed, remove the chicken from the skillet, cut it in half and finally into cubes.
Transfer everything to a large bowl and set aside.
Next, grate the potatoes using the largest holes on the grater.
Add them to the bowl with the chicken, also add the wheat flour and the egg.
Season with the salt, a pinch of black pepper and mix everything very well until fully combined.
In a large skillet over medium to low heat, add a drizzle of olive oil, the unsalted butter and stir until the butter 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, flip it using a plate.
Add the grated mozzarella cheese to half of the omelet, the egg and the slices of mozzarella cheese.
Cover the skillet again and let everything fry for another 5 minutes.
Now, fold it in half by covering the filling, cover the skillet one last time and let it fry for another 3 minutes.
Serve.