Wash and pat the cherries dry. Use a cherry pitting tool to pit the cherries. Alternatively, slice them in half and pick out the pit. Note: The compote does look prettier when the cherries are whole, so it is worth it to purchase a pitter. They are fairly inexpensive and can be found at most kitchen stores.

To make the compote, simply place the cherries, juice and sugar into a heavy-bottomed pot and heat over medium. Let the compote simmer for about 10 to 15 minutes, or until the cherries soften slightly. The cherries should still hold their shape somewhat, so it’s important to not overcook the compote.

Mix the cornstarch and a couple of teaspoons of water together in a small bowl. Once the compote has cooked, add the cornstarch a bit at a time while stirring. Let the mixture simmer for a minute or so to see how thick it becomes before adding more, keeping in mind that the compote will thicken even more as it cools. You should be able to see obvious track lines in the compote when you scrape the bottom of the pot. The compote for turnovers needs to be a thick enough so it doesn’t spill out of the turnover when you take a bite. Let the mixture simmer for a couple of minutes to cook off any starchiness. Taste to make sure it doesn’t taste chalky.

Pour into a bowl and let cool completely before using.

To begin, preheat your oven to 425° F (220° C).

To roll out the puff pastry, first sprinkle a bit of flour onto the work surface. Quickly, but gently, roll out the dough into a rectangle, about 8″ × 24″ -inches. The dough should also be between 1/8" to 1/4" -inch thick.

Keep in mind that puff pastry needs to be kept as cold as possible. If you feel that the dough is getting too warm, sprinkle a bit of flour on the back of a baking sheet and place the dough on top. Transfer it to the refrigerator or freezer to chill.

Using a sharp knife, cut the puff pastry into 4″ × 4″ -inch squares. Brush off any excess flour from both sides of the dough.

Place a piece of dough in front of you so it looks like a diamond.

Using your rolling pin, flatten the dough slightly between the left and the right points.

This just extends the dough a bit in the center, so it stretches a bit more easily over the filling.

In a small bowl, beat the egg until smooth.

Using a small pastry brush, apply the egg wash around the perimeter of the square.

Place about a tablespoon of the compote into the center. Don’t overfill the turnovers or they will leak.

Fold the dough over to create a triangle and match up the tips. Press gently to seal. Use a fork to press the seams together.

Remember, the dough should be cold while you work with it. If it feels too warm at any point, return it to the refrigerator.

Place the turnovers onto a tray lined with parchment. Transfer to the refrigerator or freezer to rest and chill for at least 10 minutes.

Once the turnovers are cold, mix the milk (or cream) with the remaining egg wash.

Using a pastry brush, brush the top and sides of the turnovers with the egg wash.

With a sharp knife, vent the turnovers by making 1 or 2 small incisions on the top.

Sprinkle the tops with a bit of granulated sugar.

Place the turnovers into the oven and bake for approximately 15 minutes or until golden brown.

If the dough is very cold (or frozen), the baking time will be longer. If the tops are getting too brown, but the puff hasn’t cooked through yet, you can turn down the heat to about 375°F (190° C) and/or rest a sheet of parchment over top until they cook through.

Once done, transfer to a cooling rack. Let cool before serving. If you want to eat them while they are still warm, be careful of the hot cherry compote inside.