Get a billy can.
Go the the camping section of an outdoor store (not chinamart) and look at the titanium cook sets. Compare them to the weight of the aluminum ones. Now look at the prices. Remember to close your mouth because your jaw has dropped.Back to the point, aside from the aluminum mess kits, what's a good idea for adding something to cook in that doesn't weigh a lot?
There is always the possible need to boil water to sterilize it, or for a hot drink, or to cook something you've caught to supplement your food supplies...I went to big 5 today and got a small stainless fry pan and pot with cup for $7. Couldn't find any made here, but haven't been to REI yet. I know cans themselves can be heated. I plan on keeping the 72 hr bag down to datrex, nothing that requires cooking. I like the tuna Mylar packs, too. For the longer term bag, I'll keep the set with the canned food bag and several sets of clothes. I guess it can't hurt to throw an iron pan in the truck, but I'll check out he titanium ones.