This is a little project that I've had bouncing in my head for a while, thought I would type out a few thoughts.

MREs are good at what they do. They're also pricey, often difficult to track down, and honestly, they're not especially appealing for eating in normal times, at least for me.

If you've got boiling (or very hot) water, you have a bunch of options - any kind of noodle or rice-base meal. Instant mashed potatoes, stuffing, etc. Add some meat - freeze dried, canned, in a pouch, etc. - and you've got yourself a meal goin'. However, this isn't exactly a meal ready to eat...it's a meal ready to cook. Don't get me wrong - we've got a bunch of these in an ActionPacker, ready to go for camping or emergencies (Mac N Cheese + can of chili is a favorite). They're easy prep and yummy, but they're not ready to eat.

So, you want food that's ready to eat out of the package. Something you could eat while hiking, riding in a vehicle, standing watch or lying low. Here's a few different approaches that come to mind:
  • Pack a bunch of snacky trail foods. Cliff bars, granola bars, trail mix, crackers, beef jerky, dried fruits, M&Ms, energy jelly beans, that kind of thing. 
  • Try to replicate an MRE with off-the-shelf stuff. Buy prepared, shelf stable stuff you can eat out of the package. Spam works. Hormel has a line of "Compleats" - packaged stews and chilis that can be microwaved or eaten out of the package (though cold Dinty Moore doesn't soud very appetizing).
  • Create a hybrid meal, using a combination of MRE-type foods and off-the-shelf stuff. You can buy loose MRE entrees and side dishes much more easily and cheaply than full MRE meals. Pick the entrees and sides you prefer, then add off-the-shelf stuff to taste. MRE heaters are also a welcome addition.
  • Go hardcore and figure out which food offers the highest caloric value-to-weight ratio. Good ol' Spam, olive oil, peanut butter and similar are options here, as are survival rations like Datrex bars. Not the most appetizing, but calories are calories.
Of these, the trail food approach is probably the best combination of cheap, easy, and good taste. You may not have the psychological comfort of a normal "meal", but you will have some good food to eat, packed with energy to keep you going. I would recommend planning on some variety and balanced nutrition for sanity's sake.

Explorers, cowboys and others have lived off these kinds of trail foods for a long time. Pemmican, jerky, hardtack, coffee and sugar were some of the "MREs" of the old days. We've got more modern options these days, but the trail foods approach is an affordable and easy option for off the shelf, ready to eat survival foods.