The raw root can be found in the produce aisle, and the prepared stuff can be found jarred in the condiment aisle. Prepared horseradish is typically made from some combination of grated root ...
If you can't find fresh horseradish, you can add fresh dill to a jar of ready-made horseradish cream. For the beetroot salad, bring a large pan of water with a tight fitting lid to the boil ...