Apple Galette is an open-faced, free-form apple pie - no need for a pie pan!
We baked it at 425F for 20 minutes, until the pastry just began to brown. Then we dialed back the heat to 350F and baked it for another 11 or 16 minutes (I can't remember which!). The recipe in the book said to bake it for 5-10 minutes, while the recipe online says 20-30. Our apples began to brown, and we decided we didn't want them to burn. After removing the galette from the oven, we brushed it with the remaining butter and let it cool before serving.
Adapted from the Joy of Cooking