Preheat the oven to 200 degrees Celsius (392 degrees Fahrenheit).
Chop tomatoes, sun-dried tomatoes, and mozzarella into small cubes and mix them in a bowl with the ham. Finely chop the basil and fold into the mix.
Divide the dough into the desired number of pieces and roll each piece out into a flat, round circle, 3-4mm thick.
Distribute the filling on the circles – place it on one side of each circle, leaving a couple of centimeters free at the edge. Season with oregano, salt, and pepper.
Fold the other half of the circle over and press the edges together well.
Place on a baking sheet, brush with milk, and bake for 20 minutes in a preheated oven.