Wash the beetroot, cook in salted water (approx. 1.5 hours) and peel.
Dice the beetroot, put in a saucepan with sugar, curry, salt and vinegar, puree and then bring to the boil. Simmer until thick and stir in the fresh horseradish and lemon juice and season to taste.
Pour into screw-top jars while still very hot and let cool upside down.