Proper, old-fashioned, serious mash
Mash worth eating is not an exercise in subtlety. There’s nothing understated about it, and requires the use of both butter and cream or, at the very least, milk.
Then there’s the texture. You can hammer away with a potato masher, of course, but if you want a headstart on smooth mash use a potato ricer. It’s like a garlic press from the land of the giants. You don’t need to peel the potatoes before you cook them because the ricer will press the flesh out and leave the skin behind, and because they’re not waterlogged, you'll end up with a naturally fluffier mash.
If you’re making mash to go alongside something else, get your timings lined up so that the mash doesn’t have to sit around. It should be moving straight from pot to plate as soon as it’s ready as it will be moving directly to mouth at a similar speed very soon after.
As to the type of potato to use, I get the best results with Dutch Cream and King Edward varieties, which are common and available internationally. Steer away from very waxy potatoes like Kipfler, Charlotte and those little new or "cocktail" potatoes.
Proper, old-fashioned mash
250g (10 oz) potatoes, washed and unpeeled
60ml (¼ cup) cream or milk
1 tablespoon unsalted butter
sea salt flakes
freshly ground black pepper
Put the potatoes in a roomy saucepan and cover with cold water. Bring to the boil, turn down the heat and allow them to simmer away for 20 minutes. They’re cooked when tender to the point of a knife blade. Drain into a colander.
In the same pan, over low heat, melt the butter and add the milk to warm through.
Push each potato through the ricer directly into the milk and butter.
Stir everything together, slowly at first to incorporate and then more briskly. This will whip some air into the mash and improve its fluff and texture.
Grate in a little fresh nutmeg. Add salt – potatoes need salt, so start with ½ teaspoon if using flaked sea salt – and pepper.
Taste, adjusting seasoning. If you think the mash would benefit from a little more butter, which is highly likely, stir it through now.