Preheat oven to 400°F. Line rimmed baking sheet with parchment paper and set aside.
In a medium bowl stir together Chobani and peaches and set aside.
Beat together egg, water and salt and set aside.
Sprinkle a cutting board with 2 T sugar. Place a sheet of puff pastry on the board and lightly roll until ⅛-in thick. Cut pastry into 4 squares and transfer to baking sheet. Repeat with second sheet of puff pastry.
Place 1 T jam in the center of each square. Divide peaches evenly among squares. Brush two edges with egg wash. Fold top over to make triangles, press edges shut and crimp with an upturned fork.
Brush tops of turnovers with egg wash and sprinkle with remaining sugar. Bake until golden and puffed, 15 to 18 minutes. Cool completely before serving.