A little bit of this winter root mash goes a long way – make it a day ahead and cut the stress on Christmas Day

Ingredients

650g parsnips
Parsnip

, cut into even chunks
650g swede
Two slices of swede

, cut into same size chunks as the parsnips
142ml tub soured cream
1 rounded tbsp hot horseradish
Horseradish root on a wooden chopping board

(English Provender is good)
2 tbsp fresh thyme

leaves    butter
Butter
Butter     , for greasing

For the butter topping

50g butter
1 small onion
Onion

, finely chopped
50g fresh white breadcrumbs (from about 4 slices)
a small handful thyme
leaves, plus extra for scattering
25g parmesan
Parmesan     , coarsely grated

Please see the 2nd Page for Directions