What to do with horseradish?

Last summer I bought a piece of horseradish and stuck it in the ground. It grew. I dug it up in the spring and planted it somewhere else and it died, but later on it came up again where I had originally planted it. I just left it there, I liked the big leaves, but now I want to dig it up and eat it.

But I don't know how. I've only had it as a cream sauce on steak. Anyone know of ways to use fresh horseradish?