Preheat the oven to 220°C.
Boil sliced potatoes in salted water until soft.
Drain potatoes and shake in a colander to fluff the edges.
Melt beef dripping with horseradish, salt, and pepper in a saucepan.
Score the beef all over with a sharp knife.
Layer chopped vegetables in a tray with beef on top and place potatoes in a separate tray.
Ladle most glaze over meat and vegetables then roast at 220°C for 20 minutes.
Reduce oven to 160°C, baste meat, and add glazed potatoes to the oven.
Roast for two hours, basting the meat every 30 minutes.
Rest the meat under foil for 30 minutes before serving.