Simply put, fresh horseradish is a vegetable ... relative), it's the plant's roots that we love to eat. You can buy prepared ...

Buy firm, fresh horseradish roots in whatever quantity you wish. Since the sauce will freeze well, it is more efficient to process a larger amount at once if you will be using a lot in about a year.

a kilogram of fresh wasabi can cost you 25 times as much as fresh horseradish. Because of its price the "wasabi" you're used to is probably just a mixture of horseradish, coloring, and sweetener.