In a pan whisk together the milk, cream, glucose, vinegar and egg yolk. Bring up to 86°C. Take off the heat and add the horseradish to taste. Season with a little salt. Pass through a chinoise into a bowl over an ice bath and allow to cool. When the mixture is cold and thick, transfer to a plastic container and freeze.
When frozen remove from the freezer and cut into 10 even-sized oblon