Peel the parsnips and cut into small cubes. Heat the fat, sauté the parsnips in it and pour in the vegetable soup.
Steam for approx. 5-10 min. Then blend well with a hand blender. Parsnips bind very well – the sauce therefore gets a very creamy consistency. Finally, stir in the horseradish and mustard and season with salt and a little pepper.
Thanks to the horseradish and parsnip flavor, this sauce is an ideal complement to boiled beef and roasted potatoes.