My favourite challenge for the uni assignment I did a while back was the one where I had to choose an unfamiliar cooking method. Because I couldn't think of much that I hadn't tried before, I decided to go all out, attempting sous vide.....without the machine.
For those who do a bit of light food reading, you probably have heard of the beer cooler (esky) solution in which an esky is used for the water bath (apparently it does a great job at keeping water temperature stable) and ziploc bags for sous vide bags (it doesn't quite make a vacuum, but is close enough to do the job). Unfortunately, recounts of coolers looking misshapen after such experiments as well as official statements from the Ziploc bag company clarifying that their bags were not for use in high temperature environments scared me away, despite how genius it did sound.
Instead, I formulated my own solution, using sealable oven bags (designed for high temperature environments) to place the steaks in. It worked particularly well as the thin plastic seemed to stick to itself quite well, thus making its own 'psuedo-vacuum' if I may. For the warm water bath, I had a thermal cooker on hand, which is like a giant thermos.