Clean the broth vegetables and cut them into coarse pieces; Peel the onion and cut into rings; Cut the lemon into slices
Pour two liters of water into a large pot, as well as add pieces of vegetables, onion, lemon, salt, vinegar, wine and spice
Let the blue broth simmer gently for about 20 minutes
Cooking potatoes
Add the fish to the broth; important: now the broth must no longer boil
Pull the trout for about 20 minutes until done
Meanwhile, melt the butter in a saucepan and brown lightly
Arrange trout; enjoy with potatoes, butter and horseradish after cutting