I make (Thai) green curry (eggplant, etc.) and I freeze it. In your case, it will thaw out nicely in your cooler and will last for hours.
Yellow curry would be good, too.
How long have you known him? Did you give him a serious look after he said, "oh I'm kidding!" or did you laugh along with him? Did he ever joke like this before? If you know him well - just tell him that you care about him and you took his statement seriously (and go on from there).
Meanwhile, go here http://dgrin.smugmug.com/Tutorials/Shooting-Tech-and-Tips/Sunny-16-Rule-Estimating/3762805_fpgXr
If you use negative film - you can be "off" for a few stops and still is printable.