1.5kg potatoes

1 celeriac (800g)

25g unsalted butter

2 tablespoons semi-skimmed milk

Peel the potatoes and celeriac, chop into even-sized chunks and place in a large pan of salted water, ready to cook.

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.