Finnish fish and bacon pie baked in rye crust (Kalakukko)

1. Knead the rye flour with the salt, lukewarm water and half the melted butter into a firm, smooth dough; if it is sticky, add a little more flour.

2. On a floured surface roll two-thirds of the dough into an oval about 1 cm thick and layer the salted fish fillets and thinly sliced bacon in the middle, finishing with bacon on top.

3. Fold the edges of the dough up over the filling, roll out the remaining dough as a lid, place it on top and carefully seal the edges with wet hands so there are no gaps anywhere.

4. Bake on a lined baking tray at 200 °C for 1 hour until the crust has set; patch any cracks with a little dough.

5. Brush the top with the remaining melted butter, wrap in foil and then in a tea towel and bake at 125 °C for another 4-5 hours.

6. Let it rest, still wrapped, for 30 minutes, then cut a circle in the top to open it and serve the filling together with slices of the crust, with butter and cold milk or buttermilk.

Tip: Kalakukko is the pride of Savo in eastern Finland: the thick rye crust acts as an "edible pot" that keeps in the juices of the slowly steaming fish and bacon. Originally it is made with whole vendace (muikku), whose bones soften completely during the long bake; perch fillets work well too. Don't skimp on time - the long, low bake is the whole point, and the pie also makes a great cold packed lunch.