Cook berries, lemon juice, and sugar in a heavy bottom skillet on medium high heat.
After about 4-5 mins, smash up the berries.
Mix the cornstarch and water together creating a slurry.
Pour that mixture over into the pot and stir.
Cook on medium low heat allowing it to reduce to a jam consistency.
Let sit for 7-10 mins.
Using a small bowl and a knife, cut out circles of the pie crust.
Make the circles as close together as possible.
Roll up any additional dough and roll it out to make more circles.
Place dough on parchment lined trays.
Create an Egg wash (1 egg + 1 tsp water) to seal.
Fill each circle with 1 tsp jam + 1 tsp mascarpone cheese.
Fold over and close with fork
Vent the top of the crust with a small slit.
Brush the top with egg wash and Sprinkle with sugar.
Bake at 375 to 20-25 mins.
Notes
Watch how much filling is added to the pie crust. It will certainly seep out but its still delicious. Using a mascarpone cheese helps cut some of the sweetness in the blueberry compote. This can be made without the mascarpone cheese.