Wash and clean the Fresh Mussels (1 kilogram). Remove any dirt which has crusted on the shell, then place them in a large pot and cook on medium heat covered with a lid until they open up.
As soon as they open, turn off the heat, transfer the mussels with their shells into a plate and filter the water into a glass. Set aside.
For the filling, in a large bowl place Egg (6), half of the filtered water, 1 clove of mincedGarlic (1 clove), Fresh Parsley (1 tablespoon), Ground Black Pepper (to taste), Pecorino Romano Cheese (3 tablespoon), and Breadcrumbs (as needed). Mix all the ingredients together adding more breadcrumbs to get a wet but dense paste. If needed add some Salt (to taste). Set the mixture aside and wait for 10 minutes.
Use the mixture as filling to stuff the shells of the mussels. Be generous!
In a large saucepan heat Extra-Virgin Olive Oil (to taste) with the Onion (1), and 1 clove of minced Garlic (1 clove).
When golden brown in color add Tomato (400 gram). Add the remaining filtered water, some Ground Black Pepper (to taste) and let the sauce simmer for about 15-20 minutes. Add more water if needed.
Add in the mussels and keep cooking for 10 more minutes with the lid covering the pan but leaving a little side open to release any extra steam.
Turn off the heat and add some Fresh Parsley (1 tablespoon). Serve them up with some toasted garlic bread! They make a great starter! Or you could use the sauce to dress some paste! It will be So flavorful you will love it.