This recipe works great as a stand-alone dish, but also as a component in Jamie’s Christmas Party from Together – see the full collection of menus here.
ON THE DAY Peel the potatoes and celeriac, chop into even-sized chunks and place in a large pan of salted water, ready to cook.
TO SERVE Bring the water to the boil and cook for 15 minutes, or until soft. Drain and leave to steam dry for 2 minutes, then return to the pan and mash well. Stir in the butter and milk, then season to perfection, tasting and tweaking. Once made, you can put the mash in a heatproof bowl, cover with tin foil and place over a pan of gently simmering water to keep warm, until needed.