For the onion rings, mix together the dry ingredients, add eggs and beer gradually until the desired consistency.
Heat the oil in a deep fryer to 180°C/350°F*.
Dip onion rings into the batter mix, then carefully into hot oil. Deep fry until golden.
Sprinkle with salt and serve with horseradish sauce.
For the horseradish sauce, mix together all the ingredients and refrigerate for 30 minutes or until needed.