These pies will blow you away whether you use wild blueberries or cultivated ones. If you have leftover filling, serve it over ice cream.
1/4 cup water
1/4 cup sugar
4 cups (2 pints) wild blueberries
2 tbsp cornstarch
1 tsp lime zest
1 tbsp lime juice
Pinch of salt
1 lb (450 g) pre-rolled puff pastry (2 10-inch square rolls), cold
1 egg, beaten with 1/2 tsp salt
1 tbsp icing sugar
1/2 cup ricotta cheese
Arrange racks in upper and lower thirds of oven. Preheat to 400 F. Line two baking sheets with parchment paper.
Bring water and sugar to boil in a small pot. Boil for 2 minutes, then add 2 cups of blueberries. Simmer until blueberries just begin to soften, 1 to 2 minutes.
Add in cornstarch and bring to boil, stirring. Stir in remaining blueberries, lime zest and juice and salt. Remove from heat and cool.
Unroll one square of puff pastry onto a lightly floured surface. Cut into four squares. Brush with beaten egg mixture. Stir icing sugar into ricotta. Spread the centre of each square with 1 tbsp ricotta mixture.
Scoop 3 tbsp blueberry filling onto ricotta. Fold each pastry over, forming triangles. Place pies on prepared sheet and transfer to the fridge to chill for 30 minutes. Repeat with remaining dough and filling.
Dip fingertips in flour and crimp edges of chilled pies to form a seal. Brush with more egg and sprinkle with sugar. Prick the top of each pie with a fork a few times.
Bake for 15 to 20 minutes or until pastry is browned and filling is hot. Remove from oven and let cool.
Serve with ice cream.