Drizzle the beets with olive oil and a splash of water. Place in a small ovenproof dish, cover with foil and roast in the preheated oven until just soft. 1 to 1 ½ hour, insert a knife and it should have no resistance going thru. Allow to cool and remove the outer skin.
In a small bowl mix together the horseradish and crème fraiche, salt and pinch of salt. Mix well and tasting as you go along until the sauce it is the way you like it.
Cut the beets, place on a dish. Sprinkle a small amount of olive oil over it and serve the horseradish sauce alongside. Add a couple of pinched of the purple radish sprouts