Combine the flour , baking soda, salt and sugar in a small bowl; mix well. Then combine the cottage cheese with melted butter, milk and egg in a big bowl; rub in the flour mixture. Lightly knead just until pastry holds together. Form a ball of pastry, wrap and refrigerate for 30 minutes.
To prepare filling, combine filling ingredients; mix well. The consistency should be thick not liquid.
Halve pastry. Place the half on a large sheet of grease proof paper. Roll the pastry into a circle, until it is about 0,2 inch thick. Carefully transfer the paper with the pastry to a baking tray.
Roll the other half of pastry on a sheet of grease proof paper.
Spread the filling over the first half of pastry to within 1/2 inch of the edge. Carefully cover the filling with the other half of pastry (turn the sheet of paper upside-down). Pinch the edges to seal. Use a sharp knife to cut some holes to allow steam to escape. Brush the top lightly with egg yolk and 1 tablespoon milk.
Bake for 30-35 minutes, until the pie is golden brown.
Place on a wire rack, cover the pie with a tea towel for 20 minutes. Serve warm or at room temperature.