Mix the flour with salt.
Add pieces of butter. If the butter is refrigerated, first melt it in a small pan. Stir it well into the flour using a fork or your hands. The mixture you get should be similar to breadcrumbs.
In a separate bowl, whisk together one whole egg and one egg yolk. Add 0,4 cup of water (100 ml) and add it to the flour with butter. Mix well to get a soft dough.
Sprinkle a flat, clean surface with flour and transfer the dough. Knead for at least 8 minutes until getting a soft and smooth ball of dough.
Place the dough in a bowl, cover with plastic foil and allow it to rest in the refrigerator until the butter solidifies (for about 30 minutes).
Preheat the oven to 356 F/ 180 C.
Prepare the filling - cut or shred the mozzarella, slice the tomatoes and mix the basil with a tablespoon of fresh parsley and garlic, all combined with a tbsp of olive oil.
Once the dough is chilled, sprinkle a clean surface with flour and roll it out (about 0.2 inches thin) using a rolling pin.
Cut out empanada discs using a bowl about 4 to 6 inches in diameter. Top each of the discs with the filling and fold it over.
Press the edges of the discs to the surface and start twisting and curling the edge from one side to the other. For each curl you make, press the dough once again to the surface. Curl the edge all the way to the other side.
Place the empanadas on a baking sheet and cover them with egg wash, using the leftover egg yolk.
Bake at 365 F/ 180 C for 20 to 25 minutes.
Allow the empanadas to settle for a minute and serve with your favorite sauce.
Enjoy!