8 large carrots, chopped into 3
3 tbsp grated fresh horseradish
8 large parsnips, sliced into thirds lengthways
2kg/4lb 8oz Maris Piper potatoes, sliced into thirds
600g/1lb 5oz beef dripping
2 tbsp black peppercorns
2 tbsp sea salt
3.5kg/7lb 11oz rib of beef