Clean and wash the leek and cut into rings. Melt the butter and sauté the leek in it. Deglaze with the broth and let cook for 10 minutes with the lid on. Fold the horseradish into the leek and pour on the cream. Tie a little with the sauce thickener and season with salt, pepper and lemon juice. Finally mix in the chopped dill.
I actually never really liked leek vegetables until I found this recipe. Tastes super delicious e.g. with meatballs.