6 medium potatoes, peeled and cut into chunks
1 large swede (rutabaga), peeled and cut into chunks
Boil swede and potatoes separately for around 30 minutes until soft.
Add butter and enough buttermilk to give a creamy consistency.
Add salt to taste.
We ate this with the honeyed Welsh lamb and roasted leeks. The original recipe used turnips, but suggested swede as an alternative.