Think you need a specific size of pan if you want to bake a pie or tart? Think agaib, Amanda Hesser of Food52 shows a simple trick to turn any pan into the size you need using only aluminium foil.
You take a sheet of aluminium foil and fold it lengthwise until it forms a thin strip. This strip is going to be the barrier in any tray with sides. Lay your dough into the sheet and adjust the strip to get the size you want. Hesser explains the finer points in the video, such as trimming the edges and getting the right size, so check that out.
How to Hack a Tart Pan [Food52]