Try looking up a thread titled something like: "non cooler based food" posted by junglesmacks...it has tons of good suggestions, it may be "easy non cooler based food"...js doesn't mind if you stalk his profile to find the info, haha, I asked him.
He's got some really good, pragmatic threads started on a few other important subjects too...big box truck method vs costly RV and probably a LOT of body lighting, plus a few other funny surprises.
Tuna! canned or special flavored foil packet (maaayyybbbeee fresh can be had, roving, always roving...it swims around a bit out there, lol) tuna is easy; salt, protien and fat.
Pancake mix, water only, lightly oil the pan, super easy to make and clean up, skip the butter and lay on the syrup!
I'm the MAN in a truck, burner who is stuck, you're in luck! I'll whip out my BIG tow chain and not charge you, not even one lousy buck!