Using your food processor, combine the flour, salt and butter and pulse for about 5 seconds. Sprinkle the ice water over the flour mixture and pulse until the pastry just begins to come together, about 10 seconds; you should still be able to see small pieces or specks of butter in it.
Transfer the pastry dough to a lightly floured work surface, gather it together to combine everything, divide the dough in half and shape into 2 mounds. Wrap individually with plastic wrap and place into the refrigerator to chill for at least 30 minutes to one hour.
Once chilled and ready to use, remove the pastry dough balls from the refrigerator, transfer to a lightly floured work surface and, using your rolling pin, roll it out to a circle (roll to whatever size you desire keeping in mind you will fold over the outer edges of the crust to form the galette, leaving a 2-inch border all around.) Using your rolling pin, transfer the rolled out pastry dough to your baking sheet. Make sure you are assembling the galette on your baking sheet, otherwise it will be difficult to transfer it after the filling is in.
Fill it (check out some of the recipes below) with your filling, fold over the dough edges, brush with egg wash or heavy cream and bake it at 400 degrees for about 35 to 40 minutes, or until the crust is a lovely golden brown and is cooked completely.