Peel potatoes, cut in half or quarters and cook in boiling salted water for about 20 minutes. Wash and clean the Brussels sprouts. Cook the sprouts in boiling salted water for 18-20 minutes. Mix buttermilk, olive oil and 25 g sour cream until smooth, crumble goat's cheese into it, season with a little salt.
Drain the potatoes and let them evaporate briefly on the switched off hotplate. Add stock and 50 g sour cream, mash to puree. Season to taste with salt, pepper and nutmeg. Drain the Brussels sprouts and season to taste with salt, pepper and nutmeg.
Arrange sprouts and potatoes in a bowl, sprinkle with buttermilk mixture and dust with paprika powder.