Start by cutting the tomato into strips and set aside. Do the same to the onion and set aside.
In a bowl, add the eggs and mix them well until combined, add 1 pinch of salt, the milk and mix again.
In a skillet, add the butter and stir until melted, next, add the onion strips and fry them until wilted.
Put the onion strips together in the center of the skillet, arrange the tomato strips around them, season with one pinch of salt, pour in the beaten eggs, add one pinch of black pepper, cover the skillet and let it all fry for 5 minutes.s
After this indicated time, add the grated mozzarella cheese, oregano to taste, cover the skillet again and let it all fry until the cheese has fully melted.
Serve.