depends where you live. if you have mild winters, you can grow radishes, turnips, carrots, rutabagas, beets, all the leafy greens, brussels sprouts, cabbages, cauliflower, broccoli, peas, and leeks, among other things. I would focus on the calorie rich root crops like carrots and rutabagas if you are focused on survival planting. They sit in the ground for a long time till you need them and they store well too. Leafy greens grow fast and will provide tons of nutrients. You can grow them quickly and dry them for long term storage.

If you live where there are harsh winters, not sure if you can do anything, I don't have experience in those zones.