Dump flour sugar, salt and lemon zest into the bowl of a food processor.

Pulse just to combine.

Add butter and pulse until the consistency of coarse sand.

With blade turning, slowly add ice water until it forms a ball.

Depending on the weather, you may need to add more or less.

Wrap dough in plastic wrap, form into a disc, and chill for one hour.

In a large mixing bowl, combine blueberries, mango, salt, sugar, flour, cinnamon, and lemon zest.

Toss until all fruit is coated and set aside.

Preheat oven to 400 degrees F.

Roll out dough on a floured surface to approximately 12” circle.

Transfer to parchment lined baking sheet (Make sure baking sheet has a lip to catch any fruit juice that may leak during baking).

Pour filling into the middle of dough.

Spread evenly, leaving about 1-2” around the edge.

Fold edges of dough over filling, forming a rough circle and gently pressing to seal dough around filling.

Combine egg and water in a small bowl.

Brush pastry dough with egg wash and sprinkle with sugar.

Bake for 45 minutes.

Cool completely before cutting.