Prepare everything necessary. The dough should be at room temperature.
For the filling, thaw the cherries, remove the pits, drain the juice into a cup. Transfer the berries to a saucepan, add sugar, cinnamon.
150 g cherry, 60 g sugar, ¼ tsp cinnamon
Bring to a boil, add diced apples.
150 g apple
Bring to a boil again. Dissolve the starch in cherry juice and, stirring constantly, pour it into the saucepan in a thin stream.
1 tbsp starch
In a couple of minutes, the starch will cook and the filling will thicken.
Lay the puff pastry (cut off a small section for decoration) in the form, here the diameter is 20 cm, if necessary, roll it out a bit. Form the edges. Sprinkle the bottom with starch, a couple of pinches will be enough. This starch forms a kind of barrier between the dough and the filling, and will not let the dough get soggy.
300 g puff pastry, 1 tbsp starch
Lay out the cherry-apple mass.
Form a decoration from the previously reserved dough as desired.
Brush with yolk.
1 pc egg
Bake in the oven at 170℃ for 30 minutes. The filling is very liquid when hot, so be sure to let the dessert cool down a bit, at least to a warm state. A warm pie with apples and cherries made of puff pastry is very tasty complemented with ice cream.