Preheat the oven to 425°F. Line a cookie sheet with parchment paper.
Let pie crust stand on the counter for about 15 minutes to come to room temperature.
Place peach slices into a medium size mixing bowl. Add zest and juice, toss well.
Using a large spatula, stir peaches with cornstarch, sugar, nutmeg and salt. Mix well. Gently fold in the raspberries.
Unroll the crust onto a silicone mat and roll into a 10 inch round. Move to parchment lined baking sheet.
Arrange the fruit filling in the middle of the crust leaving a 1 ½ inch border.
Fold edges of crust over the filling, folding as needed. Brush edges with egg. Sprinkle with turbinado sugar.
Bake at 425°F degrees for 25 minutes then lower the oven temperature to 375°F and continue to bake for another 15 minutes.
Let baked galette stand on counter for 15-20 minutes before cutting.
Serve warm with a big scoop of vanilla ice cream or fresh whipped cream.