I’m used to seeing horseradish in a glass jar, usually dyed bright red. When I saw this octopus-like root at the Grand Army Plaza Greenmarket I wasn’t sure what it was at first. Cultivated since the times of ancient Greece, horseradish is even more pungent in its fresh form — you just have to grate it to release those sinus-clearing enzymes. What you grate it over is up to you, though I’m sure my family would recommend gefilte fish.