Quite possibly the easiest thing to grow:  green onions, a/k/a scallions, sometimes called shallots in south Louisiana (not to be confused with bulb shallots–another plant entirely).  Next time you use a storebought bunch of green onions, trim off the root ends about 1″-2″ above the rootlets.  Stick these bits directly into the ground, or into a pot of soil.  Water generously, and soon shoots will appear.  In a few short weeks, the onions will grow lovely tops, ready for harvesting.  Cut off at ground level, and the onions will provide you with crop after crop, if provided with sufficient moisture.  Too lazy or forgetful to water?  Plant a mini onion patch under the drip line of the roof overhang, or the drain outlet of a window air conditioning unit, or near that dripping garden hose bib.

Green onions feature prominently in so many Louisiana specialties; why not create a ready backyard supply of your own?