I just came back from doing this...sort of...we had a travel trailer with propane (stove, small refrigerator)...My staple, cheap meal has been a brown rice, bean, onion and tomato type dish...add any kind of meat, if available....tobasco, garlic, salt...done. I found that canned beans worked better for me, I didn't have the time or propane to boil beans for an hour.
Lentils are cool...I did a similar deal...diced tomatoes, onion...I would throw some shredded cheese in the mix if I had some to thicken it up and add extra flavor...
Oh, don't forget them campfire pies...bread, butter, canned pie filling, little bit of powdered sugar...make sure ya have your pie irons in your survival gear...can't beat that...
Don't forget dry munchies...nuts, pretzels, dried fruit, etc.... ya can pop some of these instead of lunch...
Of course, in the end the most important item is coffee. A french press is the best thing those French folks ever invented...couldn't stand the stovetop percolator, ick...Now, that I'm back to having power and can use my coffee maker, I'm still using my french press...I'm addicted... I think it's the equivalent to what crack did for cocaine...