For the pastry dough: Put the flour and salt in a large bowl. Add the grated butter. Pinch quickly to combine with the fingers to create a coarse, crumbly mixture. Make a well in the center. Add the eggs and 1 tablespoon ice-cold water. Quickly mix into the flour, just until the mixture holds together. Do not over mix. Divide into 4 balls and flatten into disks. Wrap in plastic wrap and let rest in the refrigerator 30 minutes before using.
For the meat filling: Put 1/2 cup/125 ml water in a saute pan and quickly bring to a boil. Combine the ground pork, ground veal, onion, garlic, some salt and pepper and summer savory together in a bowl. Stir into the water. Cover, and cook until the meat is done, about 20 minutes. Remove the lid, stir in the breadcrumbs and continue cooking uncovered until the liquid has evaporated. Check the seasonings, and cool.
Heat the oven to 450 degrees F/230 degrees C.
Roll a disk of pastry dough into a rectangle. Spoon a generous stripe of meat filling down the middle of it. Fold the short ends, up over the meat making sure to trim any excess pastry dough, otherwise it will be too thick. Then fold over the long ends so that they overlap to seal. Again, trim any excess pastry dough so it will bake evenly. Turn the log onto a baking sheet, seam-side down. Make a few slits in the top to let steam escape. Brush the top with milk for a golden crust. Bake until crisp and nicely colored, about 25 minutes. Serve warm or at room temperature.