I don't know if you are remembering the recycled disposable pie pan idea that I posted here years ago or cutting up a flat pan idea that you read somewhere else.

I prefer using a strip of aluminum that I've cut from a soda can or other leftover aluminum. Why? Two reasons: The strip I've carried in is cleaner, so any water that boils up isn't carrying debris from the rocks and I can use the water for something else, like washing something. (I try to have very few dishes.) Another reason is I like to have my cooking pan horizontal, not tilted. Liquid foods will run to the side, resulting in uneven cooking. Even biscuits can be affected by a tilt.

CamperMom