Remove the meat from the fridge approx. 1 hr. prior to cooking. Preheat the oven to 120°C. Place a baking tray lined with baking paper in the centre of the oven.
Mix the mustard, oil and rosemary, season. Rub the mixture into the meat. Heat the oil in a frying pan. Brown the meat all over for approx. 8 mins., only turning when a crust has formed. Remove the meat. Briefly sauté the parsnips in the same pan. Pour in the pear juice, reduce briefly. Transfer the meat, vegetables, juice, pears and rosemary to the warm tray. Insert the meat thermometer into the thickest part of the rack.
To roast in the oven
Approx. 40 mins. in the centre of the preheated oven. Remove the meat, brush with the pear syrup. Return to the oven for approx. 30 mins. The core temperature should be approx. 63°C. Remove the meat, cover and leave to rest for approx. 10 mins. Carve the meat between the bones.
Cover and cook the artichokes in salted water for approx. 20 mins. until soft. Stir in the sour single cream, puree until smooth, season. Serve the puree with the meat and vegetables.