Directions

• Heat the oven to 375 degrees Fahrenheit. Grease a 13×9″ glass baking dish. Roll the dough between plastic wrap, into a 14 by 11-inch rectangle. Add flour if too wet and sticking to the plastic. Transfer into the baking dish, leaving the excess dough over the edge of the dish.
• Microwave the cream cheese in large bowl until softened, 20 to 30 seconds. Whisk in30 g (1/2 cup) Parmesan cheese, oil, mustard, 1 teaspoon rosemary, salt and pepper until combined. Whisk in the egg yolk. Add potatoes and shallot to the mixture, and stir thoroughly until the potatoes are coated.
• Transfer the filling to the center of the dough and press into an even layer. Sprinkle 6 tablespoons of Parmesan cheese and remaining 1/2 teaspoon of rosemary over the filling.
• Fold the dough over the filling, overlapping the corners to secure. Make sure that there are no visible holes. Lightly beat the egg white and brush over the folded crust (you won’t need it all). Sprinkle the remaining 2 tablespoons of Parmesan over the crust.
• Bake until the crust and filling are golden brown and potatoes meet little resistance when poked with fork, about 45 minutes. Transfer to a wire rack and let it cool until just warm, about 20 minutes. Cut into slices and serve warm.