Smoked ham and cheese frittata (Hungarian stlye)

For the Frittata you need a heat-resistant pan, because the preparation starts with the stove, but ends in the oven. So you need:

-8 eggs
-2 slices of smoked ham - should be a good meat and also less fat on it
-8 pinch of salt
-Pepper
-a little bit of oil
-1 small onion
-1 cup of cherry tomatoes (small kind of tomatoes)
-Half cup of chopped spinach leaves
-1/4 cup of milk
-1/4 cup of light mozzarella

Beat up the eggs with the salt, pepper and milk. Start to fry the chopped onion and ham in a minimum of oil in the heat-resistant bowl, by the way cut down the fat from the meat. If the ham does not have that much fat you can leave the fat on it, and when you will cook you can use the ham's fat (for oil). After you glazed onions and the ham is ready add the whole cherry tomatoes and the chopped spinach, spin through, leave that for a half minute. If you don't have a resistant dish containing the ingredients, then in this step pour the ingredients into a heatproof bowl, after that you can mix the eggs, sprinkle the top with cheese and bake at  800 degrees in preheated oven for approx. In 10 minutes or until it changes to colour golden brown.