Boil the potatoes for approx. 25 minutes until soft and peel them.
Add 20 g butter to the buttermilk, season with herbal salt, pepper and nutmeg and heat in a saucepan. Press the potatoes through the potato press and mix in, season again with salt and nutmeg.
Heat the remaining butter in a pan, cut the onion into cubes and fry with the bacon.
To serve, pour over the puree and sprinkle with chives if you like.