Roll out chilled dough into a 12-14 inch round that's 1/8 inch thick. Roll dough onto your pin and unfurl it onto parchment or baking mat to refrigerate while fruit is prepped.
Preheat oven to 400℉
Prep your fruit by washing, and slicing as you please. Berries can be cut in half, and peaches into 1/4 inch slices with or without the peel.
Place fruit into a medium bowl. Add citrus zest and juice, a pinch of salt, and cornstarch if needed. Toss to coat.
Melt butter and set aside. You can brown it if you'd like!
Dump fruit into center of pie dough, leaving a 3-4 inch border uncovered. Lift edges of the dough up and over fruit around the circumference. Most of the fruit should still be uncovered.
Brush dough with butter, then sprinkle sugar over the surface of the dough.
Bake for 50 minutes, or until crust is deep golden brown and fruit juices are bubbling.
Let cool until warm, then transfer to a baking rack. If the galette leaked a lot of juices, make sure to transfer before they harden.
Cut into wedges and serve warm with whipped cream or ice cream and enjoy!