The dough can be made three ways, by hand, in a food processor or stand mixer (I used a food processor).
In the bowl of a food processor (or larger mixing bowl or stand mixer) add the flour and 5 tablespoons of butter, start to mix add the salt, the parmigiano and the egg mix to combine, if needed add more butter a tablespoon at a time, move the mixture to a flat surface and knead gently to form a ball. Wrap the dough in plastic wrap and refrigerate for 30-60 minutes.
FOR THE FILLING
While the dough is chilling, slice the mozzarella into ¼ inch slices (or even a bit thinner), place in a sieve and let drain for 20 minutes.
Slice the tomatoes the same thickness and toss with 2 tablespoons olive oil, salt, pepper and 1 teaspoon of oregano. Let sit 15 minutes.
Pre-heat the oven to 400F/200C. Grease and flour or spray an 8 inch/20cm pie or tart plate.
Roll the dough into a circle and place it in the prepared pan, with the excess overhanging by about 1 inch/2.2cm. Prick the dough, spread with the pesto, top alternating with the sliced mozzarella and tomatoes (no juice), drizzle with the remaining oil and sprinkle with the remaining oregano. Roll the excess dough to create an edge around the filling to form a border.
Bake for approximately 30-40 minutes until the pastry is golden brown and the cheese has melted. Let sit 5-10 minutes and top with fresh basil leaves before serving. Enjoy!
Notes
How to store
Store any leftover crostata in an airtight container in the refrigerator. It will keep well for up to 2 days. To reheat, place slices in a 300F / 150C oven or air fryer for about 10–15 minutes to crisp the crust back up, avoid the microwave, which can make it soggy.