One trick that I've been doing lately is regrowing green onions. To start I purchased a bag of green onions from my store. As we ate through them I chopped off the bottoms with the root ends and sat them aside.
Then I just shoved them in the dirt of the garden until they were almost covered over and watered.
In just a few weeks a new set of green onions were ready! I have cut and replanted a few times over and haven't found any degradation to the plant. It continues to grow back just as flavorful as before. I don't know how long I'll continue to pick, eat, then regrow, but my goal is to continue throughout the growing season and maybe try them in a planter in the kitchen over the colder weather months.