1 kilo floury potatoes
250g-500g butter (yes, half a kilo)
250ml-500ml milk (basically you want your milk and butter together to weigh half what the potatoes weigh)
First, put down that potato peeler. That’s it, put it down. On the floor. Now kick it towards me. That’s right, nice and easy now.
Please. Stop peeling your potatoes. It’s no good for them and definitely no good for you. OK?
Right. Next, verify that your potatoes are the same size. You need to do this so that they all cook at the same speed, OK? Titchy potatoes will be cooked before the giant ones. It sounds obvious now you read it, but it isn’t unless you know it. Also, while it’s sometimes acceptable to cut up potatoes so the bits are the same size it’s not recommended from a flavour point of view – the cut surface allows water to penetrate the potato and spoil the flavour (OK, only a bit but we’re going for the best ever mashed potato here so nuances count).
Now the best kind of potato for this are Pommes Rattes. Usually you find these in fairly small sizes, about the length of your thumb, but bigger ones are best and, most importantly, peel.
Yes, peel. You will, eventually, peel these potatoes but not now, calm down big boy.
Put the potatoes in a saucepan, cover with water, add the salt. I’m always being asked how much salt – well, 10-12 grammes per litre of water is the official amount. A good three-fingered pinch of cooking salt – not table salt – is the generic, about-how-much quantity. Do use cooking salt, by the way, the iodine in table salt doesn’t do cooking flavours any favours. Remember, we’re talking nuances here – but three nuances make a wodge and four wodges make a heap of difference.
It’s going to take about 20-25 minutes to cook the potatoes, so spend the time lightly melting the butter and warming the milk in whatever proportions you like. I go for 50/50, an assertion which is enough to start a fight in the bar of most French cookery schools. Bring up ‘bouillabaisse’ if you fancy a knife fight.
When they’re cooked – test with the point of a fine-bladed knife, not the prongs of a fork – strain them and peel them. Straight away. So prepare to burn your hands – or hold them in a tea towel, your choice. You’ll find that after a little practice you can peel off just the very outer layer of the skin, the coloured part, between your thumb and a knife blade. You’ll also need to cut out any major blemishes and marks.
Now instead of mashing with a potato masher, either use a moulin a legumes, a vegetable mill, or a potato ricer. The moulin looks like a conical metal bowl with a mesh base and a stirring paddle in the middle – feed veg into the top and purée comes out of the bottom. Every French house has one, knock on any door and ask to see theirs – they’ll be happy to show theirs off and explain its use in great detail. Honest.
The potato ricer looks like a giant garlic press – pop a potato in the top, squish down the press bit and purée comes out of the bottom.
Whichever you use, let the purée fall into a dry saucepan. When you’ve puréed all the potatoes, set it on a medium heat and stir with a wooden spoon or spatula to dry the mix as much as possible. This is one of the great secrets of great mash – dry the spuds after cooking them.
When they’re dry enough (this, happily, normally coincides with the moment when you get bored and/or tired of the drying process), start adding the butter a little at a time, now beating the mix with a decent-sized baloon whisk. Heretics choose to use electric mixers at this point but they will burn in hell later for their sins.
Once the butter’s all been added, start adding the milk a little at a time. Be more careful now, this is where you’re going for your chosen consistency – which should be a little runnier than you think it needs to be. Keep whisking furiously all the time, and continue to beat your mixture when all the milk’s been added, always over your medium heat. It’s this portion of the event more than anything which will give unctuosity to the final result.
You also need to whisk like mad to emulsify the mixture – potatoes and this much milk and cream are not an entirely stable mix. They won’t go bang – that’ll be your stomach after eating your fourth portion – but they will start to separate eventually.
This method is largely based on that of the great French chef Joel Robuchon, who made purée de pomme de terre one of his signature dishes. Watch https://www.youtube.com/watch?v=qTTvZ2PW96k for all the gory details.