Add flour, sugar, butter, egg, salt and lemon juice to a food processor, pulse until you get a nice dough. Flatten it so it will be easier to roll.
Cover with plastic wrap and let it chill for about 30 minutes. This is optional: my mom doesn't make it chill, instead I do.
Let's make the sour cherry pie:
Preheat the oven at 180°C (355°F).
Remove the dough from the fridge and let sit at room temperature for 5 minutes.
Lightly flour work surface and top of the dough, then roll ⅔ of the dough using a rolling pin.
Transfer it into the pie pan then gently press it into dish. Place it into the freezer while you prepare the rest.
Into a bowl, add sour cherry preserve, a pinch of nutmeg and a pinch of cardamom. Mix and set aside.
Now roll out the remaining dough, and cut it into strips. Use your fantasy here: make them all of one size or different sizes.
Take pie out of the freezer, fill it with sour cherry preserve and start laying the strips vertically and evenly spaced, then horizontally. (check out this video)
Brush with egg wash and sprinkle some sugar.
Bake for about 30 minutes (keep an eye on it because time depends on your oven)
Serve warm, with toasted almonds and vanilla ice cream