You can get "heavy duty" foil from the bottom of many shop bought pies. Certainly here, if you buy a frozen apple pie from the supermarket, it will come in a heavy foil tray, which is meant to be disposable. You can clean it, cut it to shape and re-use it.

You can also buy new, clean trays (from the supermarket), in a variety of sizes ranging from a small bowl, to a turkey !