A plant, specifically. Encourage the genetic diversity of food crops by demanding something odd that you wouldn't normally eat. If we all demand crops that are not one of the few common breeds, it will help prevent all of our food becoming the same variety of a few crops.

Note: If you're already doing this action, take a look through each of the steps and make sure you haven't missed anything. If all's well, go ahead and check off all the boxes, then go start something new!