Canuck, because MREs aren't efficient for long-term survival due to their high packaging ratio. That aside, do you really want to be eating those for that long without ever having a properly cooked meal? It'll destroy your morale eventually.
That aside, I've got you beat! MUSHROOMS!http://www.fungi.com/kits/index.html
From this website you can order kits that can be stored for a good amount of time (they're inactive until you add water.) and can grow mushrooms right inside your underground bunker! Don't forget, mushrooms are the only proper source of vitamin D that you can grow! Furthermore, many of these will provide food within a relatively short period of time, and can be harvested off and on for a number of months at a time... and even once they've been harvested out, you can break them apart and til them into a bit of compost, straw, sawdust or the like, and they'll start sprouting up all over again! On top of that, don't forget the medicinal properties of some of these mushrooms. AND WAIT, THERE'S MORE (alright, I couldn't resist, this feels like a sales spiel...) many of these mushrooms can even be sewn in with your garden after use, which then allows them to convert materials in the soil which would otherwise be inert, into nutrients for your crops! That's right, not just can you eat them, but they make the rest of your food grow bigger and better!
Also... face it, mushrooms are simply cool to watch grow.