Method

• Make the crust: In a large bowl, combine the rye flour and salt. Cut in the butter until the mixture resembles coarse crumbs. Gradually add the water, mixing until the dough just comes together. Form the dough into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.
  
  
• Prepare the filling: In a large bowl, combine the fish, pork or bacon, onion, melted butter, salt, and pepper.
  
  
• Roll out the pastry: Roll out the dough on a lightly floured surface to a 12-inch circle.
  
  
• Assemble the kalakukko: Place the filling in the center of the dough. Fold the edges of the dough over the filling and pinch together to seal.
  
  
• Bake: Bake in a preheated oven at 400°F (200°C) for 45-50 minutes, or until the crust is golden brown and the filling is heated through.
  
  
• Let cool and serve: Let cool slightly before serving.