Wash the sweet potatoes and place in a large, non-stick stockpot (unpeeled). Cover with cold water and bring to the boil. Add a pinch of salt and cook, uncovered, until the potatoes are tender all the way through (approximately 30-40 minutes after the water has come to a boil).
Drain the sweet potatoes. Prepare a medium sized bowl to place the mashed sweet potatoes. While hot, cut the sweet potatoes in half and place cut side down into a potato ricer. Remove the sweet potato skins each time you place a piece of sweet potato into the potato ricer. Alternatively, remove the sweet potato skins (while hot) and mash using a tamis (drum sieve) into a bowl.
Heat the cream and milk in a small saucepan and bring to the boil. Return the mashed sweet potato to the stockpot over low heat and use a wooden spoon to stir for a few minutes. Add the butter and stir until combined. Add half of the cream and milk liquid and stir until combined. Add the remaining cream and milk and cook, stirring, until the mash is creamy and smooth. Add grated nutmeg to taste and season with salt.
Transfer the sweet potato mash to a serving dish – buon appetito.
1kg sweet potatoes|100ml thickened cream (alternatively, use milk)|50ml milk|50g unsalted butter|Freshly grated nutmeg|Sea salt