Peel and quarter the potatoes and cook in salted water for 20 minutes. Drain and return to the saucepan.
In the meantime, heat the milk with the butter and lemon zest.
Wash the herbs, shake dry and finely chop.
Mash the potatoes well with the potato masher and now add the milk with the melted butter, first only 2/3 of the liquid, add the rest if necessary. Mix vigorously with a whisk to a fine puree and season with salt, white pepper and nutmeg. Now stir in the herbs and serve.