Why not simply use a cooking pot and tape the lid on? Someone wrote a while back about how we all like to improvise when there is no need to. If all you've got is a Sig box ok, but why chose to use the wrong thing when you can pack a real cookpot? Or slap a kidney shaped mug on the bottom of your water bottle.
I fell into this trap and bought a pair of ponchos with cord and poles to make a tent. A few minutes of trying to put it up reminded me how awful 2 pole tents were to assemble. I could barely manage it in full daylight, with no wind and in good weather. And at the end of it what did I have? A tiny low groundsheetless, draughty, condensation wet, bug ridden tent that I got sprayed with rain in since it was barely longer than me. I went back to a proper tent.