I have banana plants at home. The leaves are huge and are used for cooking (or wrapping food before cooking). Since they're berries, when they fall from the plant the seeds make another plant so you start with one and after a couple of months there are more plants around the original.

However I still buy bananas, homegrown are not as good. For real. They're more or less like in the picture above instead of the yellow-seedless we all know.