My dream backpacking bowl would be lightweight, have a screwtop, and would accommodate two ramen noodle packets or a double serving freeze-dried meal (like Mountain House) with boiling water. The reason I'd like a screw top is to lock in the heat while the food is rehydrating without worrying about it popping off. I also like the confidence that liquid or food won't drip out of a screw top if I need to throw it in my pack before washing. Does anyone have something like this? My guess is that it would have to be plastic. Ziploc disposables makes something like this, but it only holds two cups.