Galette is not actually a pie per se although some call it a freeform pie. Rather, it is a pastry that is wrapped around fresh fruit. You do not need a pie pan for this one, just a flat surface like a baking sheet pan. The dough is a lot like pie pastry but with a bit of cornmeal.  You can use just about any fruit or even vegetables for this pastry, but it is most often done with peaches, nectarines, plums, or apples tossed with sugar and flour. You can also add lemon zest, cinnamon, nutmeg, and other spices.  To keep the bottom from being soggy, brush it with egg white or layer it with crushed cookies or cake. Then you just put it on a piece of parchment paper on a baking pan, pile the fruit into it, and fold the edges over with a large opening in the top to release the steam.