Cook the rice in water until the liquid is absorbed. Then add the milk and salt.
Simmer over low heat, stirring occasionally until the porridge thickens (about 30 minutes). The porridge should be dense. Let it cool completely (this is crucial!).
Karjalanpiirakka, literally 'Karelian pie', is a specialty originating from the historical region of Karelia. These pastries are characterized by their extremely thin dough, which becomes crispy after baking, and the filling remains creamy.
The most traditional filling is rice porridge (riisipuuro) cooked in milk, but mashed potato fillings (perunapiirakka) are also common. The pastries are usually brushed with a mixture of melted butter and milk after being taken out of the oven to soften the edges.
Cook the rice in water until the liquid is absorbed. Then add the milk and salt.
Simmer over low heat, stirring occasionally until the porridge thickens (about 30 minutes). The porridge should be dense. Let it cool completely (this is crucial!).
Mix both types of flour, salt, and cold water. Knead into a firm, non-sticky dough.
Divide the dough into 15 equal pieces and roll them into balls. Dust the work surface with rye flour.
Roll each ball into an extremely thin oval shape (about 10 cm in diameter). The dough should be so thin that it is almost translucent.
Spread 1-2 tbsp of the cooled rice porridge onto the center of each oval, leaving about 1-2 cm free around the edge.
Fold and crimp the edges of the dough towards the center with your fingers to create a slightly raised, decorative rim, while the center with the filling remains exposed.
Preheat the oven to a very high temperature, 250 °C (482 °F).
Bake the pastries on a baking sheet lined with parchment paper for 10-15 minutes, until the crust is crispy and slightly brown.
While they are baking, prepare the brushing mixture by combining melted butter and milk.
Immediately after removing them from the oven, liberally brush the hot pastries with this mixture (this softens the edges). Cover the pastries with a cloth and let them rest for 5 minutes.
To make munavoi, mix the softened butter with chopped, hard-boiled eggs and salt.
Serve the pastries warm, spread with a generous layer of egg butter (munavoi).