Horseradish is incredibly easy to grow. Tough, low maintenance, very rewarding. Leave just a piece of root in the ground after harvesting, and it grows back with a vengeance.
When it dies back in autumn/winter, dig up a root (or however many you are brave enough to tackle in one go). Wash it.
Scrape the skin off with a knife or the edge of a spoon.
Grate. Now that is the 'fun' part. You hear about the fumes of the horseradish when grating. Well, it's true. It is STRONG stuff! It starts harmlessly enough, but suddenly you get hit by the fumes and your sinuses clear, your tear ducts get incredibly busy. So, do proceed with caution. You have been warned. Oh, I am talking about grating by hand - if you have a food processor, it might be easier. But do open the lid very slowly, carefully and away from your face.
Now the basic recipe:
1/2 cup of grated horseradish
3 tbsp (white wine) vinegar
1/2 tsp salt
Put in a clean (sterilised) jar, keep in fridge. Should keep for about 4-6 weeks. I have read somewhere that you can freeze it, too.
Be very careful when tasting this batch. Start with a tiny amount, just to taste how potent it is. Enjoy!