Ziplock bag with an established culture of live microworms on a 100% potato media bed (I use actual peeled and boiled potatoes, I find that they last a lot longer without smelling compared to the boxed mashed potatoes or instant oatmeal that a lot of people use) fed with yeast. When you get the culture home, simply boil then let cool, then mash some potatoes enough to fill the bottom inch or so of a plastic container (I use a costco sized hummus container) and sprinkle some yeast on top to feed the culture (I'll include some yeast to get you started). You can also use an alternative for the media, like oatmeal or instant mashed potatoes, if you prefer. Absolute easiest live food you can culture, great for fry and small fish!