I've slowly come to realize that modern industrial agriculture has shifted the public's taste to vegetables that require value added industrial processing, which is not the same thing as having food security. For example, while chicory is a leafy green available during the cool months of the year, Belgian endive is the same plant that has had some industrial processing done to blanch it of its bitterness. This blanching process ends up increasing the inputs to the crop without adding to the nutritional value of the final product.
Another example is broccoli versus broccoli raab. Growing a large, dense head of broccoli requires a specialized climate, which is why most of the broccoli in the country is grown in the area around Santa Maria, California. The raab version of broccoli, with multiple small heads, offers more in the way of food security because it can be cut several times over a longer period than the single cutting of the conventional broccoli crop. It can also be successfully grown in areas that do not have the narrow temperature range of the central California coast.
In planning a food security garden then, one has to discard vegetables with narrow growing requirements or industrial processing inputs and replace them with other crops that yield over a longer time period or can even be stored "in the field". My recent experience growing salsify (Tragopogon porrifolius) has led me to consider it as a very good candidate for a food security vegetable. Coming into last winter, I had a few salsify plants in the garden, and they handled the Arctic Vortex winter well, surviving the 12F low in January. They are now putting on some spring growth and coming into flower, and I have been cutting the immature flower buds and cooking them like asparagus, which they are akin to in flavor. In reading up on it, I've seen where it can be cut at all times of the year and that it doesn't increase in bitterness when it begins to flower. From a food security perspective, growing large heads of broccoli is a wasted effort, whereas keeping a patch of salsify well tended will provide a long-term harvest of flower buds, leaves, and roots.
Another good candidate is upland cress (Barbarea verna), also known as 'creasy greens'. This was also one that came through the winter unscathed, and even seemed to put on some growth. I've prepared it much as one would turnip greens, and to me, the flavor of creasy greens is preferable. It's also a decent addition to salads, giving them a little kick, something that I would never do with raw turnip greens.
Both upland cress and salsify are said to easily reseed themselves, but how they do that in my garden is still an open question. I am hoping that I can establish them on my hugelbeds so that they will be sustainable in the truest sense of the word. While these two vegetables receive little attention from industrial agriculture, I can see a definite need for them in a food security garden.