Herb & pepper crusted rib of beef
Planning a dinner party? James Martin's crusted roast beef will wow your guests
Put the celeriac in a large pan of water and bring to the boil. Cook for 15-20 mins until tender, adding all the apple apart from a few pieces, for the final 5 mins.
Drain well and return to the pan, then mash until smooth. Stir through the horseradish and some seasoning. Garnish with the remaining apple slices, if desired.