Place the stock in a saucepan, over medium heat. Bring to a boil. In a small mixing bowl, combine the eggs and pecorino cheese. Season with pepper and mix well. Whisk the mixture into the boiling stock. Cook for 1 minute. Add the mozzarella cheese and parsley. Whisk well. Place 2 pieces of the bread into each shallow bowl. Ladle the soup over the bread and serve.
In a bowl, mix together the flour, the semolina, and the salt. Gradually add the water until you have a smooth dough that is very easy to shape, not sticky, and not stretchy or glutinous. You might need as little as a cup of water-it all depends of the flour and the weather. Place the plaque au four or a baking sheet in the oven. If you are using a baking sheet, put it in the oven upside down, it will be easier to slide the bread on and off.
Preheat the oven to 400 degrees F. Divide the dough into 10 small balls. Cover them with a towel and let rest for about 15 minutes. On a floured surface, roll each ball to a thickness just under 1/16 of an inch. Put each round onto a heavily floured peel and slide onto the hot plaque au four or baking sheet in the oven. Bake for 2 1/2 minutes on each side. When the bread surfaces begin to bubble, watch the bread constantly, as they can readily burn. Turn the rounds over and bake another 2 1/2 minutes. When one is very light gold with dark highlight, remove it to a rack to cool. Continue until all of the rounds are done.
This bread will keep for 2 to 3 weeks in an airtight container. When ready to serve, place the bread back in the oven for 2 minutes and they should be good as fresh. Yield: 10 rounds