Horseradish Sauce

Ingredients

• 80 g fresh horseradish root
• 200 ml double cream
• 100 g soured cream
• 2 tbsp white wine vinegar
• 1 tsp Dijon mustard
• 1 tsp caster sugar
• 0.5 tsp salt

Steps

1. 1
   Peel the horseradish and grate it finely, ideally at arm's length or outdoors. The volatile oils are genuinely eye-watering, far more so than onion.
2. 2
   Toss the grated root immediately with the vinegar. Acid stops the enzymatic reaction and locks in the heat at the level you want — leave it exposed and it fades within minutes.
3. 3
   Whip the double cream to soft peaks, stopping well before it stiffens.
4. 4
   Fold in the soured cream, mustard, sugar and salt.
5. 5
   Fold through the horseradish a spoonful at a time, tasting as you go — potency varies enormously between roots.
6. 6
   Chill 30 minutes before serving. Use within two days; the heat dulls with time.