Microwave steamed vegetables? You can get some ground beef and make a hash with some sweet potatoes and onions. Chicken thighs can be had cheap...you could sautee some of those on the camp stove one night and have those for a few days.
The good news is that with whole foods your limited $ will go further. You already mentioned eggs...that is a great start on the cheap side. You are going to have to be extraordinarily thrifty to feed two on that budget. Offal can be had for free to dirt cheap...maybe there are some crock pot options there. I'm not very crock pot saavy, but it strikes me as a reasonable thing for beef heart if you had the right recipe.
That is a tough set of requirements.