To ‘mash’ or to ‘purée’? As will be obvious to readers of this book, I belong to the latter category. ‘Mash’ is one of the ugly words of cookery.
To make a good purée, a floury potato is essential. Put unpeeled, even-sized potatoes, cut in quarters, in cold salted water, bring to a boil and simmer gently until the potatoes are cooked. The Roux brothers recommend putting a quarter of a lemon in the cooking water to prevent break-up. As soon as the potatoes can be handled push off the skins and steam dry under a cloth for 5–10 minutes on a warm stove.
Paul Bocuse recommends pushing the potatoes through a fine sieve with a pestle – but working top to bottom and never with a circular or horizontal movement. Good purées can also be made with a mouli but never with a food processor. A potato masher tends to crush the life out of potatoes – I prefer a whisk. Put the resulting purée in a clean pan and add the seasoning. Mix, using a spatula to achieve a silken finish. Warm milk, cream, egg yolk, chopped onion, olive oil, lemon juice, grated orange, yoghurt – even Guinness – are just a few of the additions that give interest and variety to purées.
Chef Joël Robuchon, whose restaurant has 3 Michelin stars, has raised potato purée to divine heights. His potatoes are puréed by hand with warm milk in a mouli, then 9 oz (250 g) of the best chilled butter is added per kilo of potatoes. The purée is then pushed through a sieve with a wooden fork.
A good purée needs no accompaniment. However, the following addition is very good. Use different varieties of mushroom if possible.