Peel apples, cut into eighths, core and cut into thin slices. Coarsely chop walnuts, up to 12 halves. Heat fat, sugar and chopped walnuts in a pot while stirring. When d
Steam for 8-10 minutes. Stir pudding powder and apple juice until smooth and bring to the boil with the apple compote while stirring. Let the compote cool down. In the meantime, place the puff pastry slices next to each other and defrost at room temperature.
Roll out the puff pastry sheets on a floured work surface into rectangles (12 x 24 cm) and cut them in half. Whisk the egg and spread the puff pastry squares thinly with it. Place 1 tablespoon of apple compote in the middle of each square and fold into a triangle.
Press the edges firmly all around with the help of a fork. Place the puff pastry corners on two greased baking trays, brush with egg and cover each with a half walnut. Bake one after the other in a preheated oven (electric oven 175 ° C / gas: level 2) for about 30 minutes.
Serve dusted with icing sugar. Makes 12 pieces.