Peel and wash the potatoes and cook them in boiling salted water for about 20 minutes. Parsnips peel, clean and roughly dice. Add to the potatoes after 10 minutes. Then drain them thoroughly and let them cool down a little.
While still warm, press through a potato ricer. Let the potato mixture cool completely, then knead with egg yolk and flour. Season with salt and macis. Form strands about 3 cm thick on a lightly floured work surface.
Divide into small pieces, shape slightly, press in lightly with a floured fork. Pour into boiling salted water in portions. Leave to stand for 4-6 minutes until they float to the surface. Wash parsley, shake dry, pluck leaves from the stalks and chop.
Melt the butter in a large pan. Add the gnocchi and fry briefly. Add parsley and toss everything. Season with pepper from the mill.