Wash and peel the beetroot (advisable to wear plastic gloves for this job!). Dry and cut into small pieces.
Blitz the beetroot in a food processor and mix with the salt, sugar, fennel seeds, honey and gin.
Pour the curing into a tray and place the salmon onto it with the skin facing towards you.
Cover with cling film, lightly press the fish and cure in the fridge for 36-48 hours.
Remove the fish, then brush off the excess cure and pat dry with paper towel.
Whip the cream until it holds its own volume, mix in the grated horseradish and season with cracked black pepper.
Place the salmon on a chopping board and slice thinly at an angle.Arrange onto a plate and serve with the horseradish chantilly. Garnish with a few rocket leaves and a fresh lemon.