1Cut the butter into small pieces.
2Place the flour in a bowl, add the butter and salt. Incorporate the butter using your fingertips. Gradually add ice water and mix to a smooth dough. Wrap with plastic wrap and store in the fridge for at least one hour.
3Peel the pears, cut them into small cubes. In a large bowl, toss the pears with the gorgonzola (also diced) and rosemary, mix gently then pepper to taste.
4Preheat the oven to 400 ° F.
5Remove the dough from the refrigerator, let stand for 10 minutes before rolling it out on a lightly floured surface. Cut out circles with a cookie cutter.
6On a baking sheet lined with parchment paper, place half of the dough disks. In the center of these dough disks, place a heaping teaspoon of the pear and gorgonzola mixture. Using a brush dipped in water, moisten the edge of the dough around the filling. Cover with a second disc of dough. Press well to seal the dough on the sides, making sure to get all the air out of the pie as you go. To get an extra good seal, use a fork to press the dough.
7Stir the egg yolk with a little milk and brush over the top of each pie. Make 4 small incisions with a knife on top of each pie. Cook for about 20 minutes, until the dough is golden brown.