Creating your Crispy Pancetta and Potato Crostata is straightforward if you follow these steps:

1. Prepare the Dough: Preheat your oven to 400°F (200°C). Roll out the pie crust dough into a 12-inch circle and transfer it to a pie or tart pan.
2. Cook the Pancetta: In a skillet, heat the olive oil over medium heat. Add the diced pancetta and cook until crispy. Remove from the pan and set aside, leaving the drippings.
3. Sauté the Onions: In the same skillet, add the sliced onions. Cook until they are caramelized and soft, about 10 minutes. Season with salt and pepper.
4. Layer the Potatoes: Arrange the thinly sliced potatoes evenly over the pie crust. Season them lightly with salt, pepper, and rosemary.
5. Add the Pancetta and Onions: Spread the cooked pancetta and caramelized onions over the potatoes, followed by the shredded mozzarella cheese.
6. Fold the Edges: Gently fold the edges of the pie crust over the filling, leaving the center exposed. Brush the crust with the beaten egg to give it a golden finish.
7. Bake the Crostata: Place the crostata in the preheated oven and bake for 35-40 minutes or until the crust is golden brown and the potatoes are tender.
8. Cool and Serve: Remove from the oven and let it cool for a few minutes. Slice and serve warm.

By following these instructions, you’ll end up with a beautiful and tasty dish that’ll impress everyone at your table!