Ever notice how supermarket stock runs right down over Christmas or long weekends? You can walk in sometimes and there's no bread, milk or meat - fresh or otherwise. Now imagine if the shops were always like that, and there were queues for basic food items. Now imagine if the basic necessities were rationed (such as in World Wars I and II).
You can stockpile all you like, but nothing will ever replace the vitality of good fresh food. So how do you go about producing the right kind of food, and enough of it, independently of the commercial food chains?
Aquaponics is one exciting solution - an enclosed system where fish and vegetables thrive in a water-rich environment, complementing each other.
A nice adjunct to this could include chickens and a worm farm, which could easily be intergrated.