Peel beetroot (it is best to wear rubber gloves). Season with salt, pepper and dried thyme and wrap each tuber firmly in parchment paper. Place the packets side by side in an ovenproof dish or roasting pan.
Cook in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 45 minutes. Remove from oven, place on plates, open parcels, cut beetroot into slices, add crème fraîche and garnish with thyme.