For the best mashed potatoes, choose a floury potato like the Bintje or the Challenger. The Ratte is also suitable for mashed potatoes. A floury potato contains a higher percentage of dry matter (starch), which ensures that a mealy potato results. This is what you need for good mashed potatoes.
Peel the potatoes, cut them into small pieces and cook them. Drain the potatoes immediately and allow them to dry.
Mash them with a masher, adding some milk if needed. Make sure that the milk is hot. Cold milk will ruin your mashed potatoes. Be sparing with it! Use part milk, part cream, to obtain creamier mashed potatoes. Mix everything thoroughly, adding an egg yolk and a pat of butter, mixing these in with a sturdy whisk. The whisk is essential for fluffy mashed potatoes. Pepper, salt or nutmeg can be added for flavour.
Tip: Boil the potatoes in stock or broth rather than water! You can also add sprigs of rosemary to the water, but if you do this do not use the nutmeg.