Mix half of the soup with the cornflour.
Put the rhubarb in a saucepan with the remaining sugar, ginger, clear soup, mustard, balsamic vinegar and grated lemon zest and steam with the lid closed for about 2 min. Add the finely chopped horseradish leaves and steam again for 2 minutes. Whisk well with a hand blender and thicken with the starch mixture. Let it boil up briefly and season.
Cut the pike-perch fillet into 5 cm cubes, season lightly with pepper and wrap with the bacon slices (barding). Cook the wrapped fish cubes on both sides in a grill bowl or directly on the grill. Serve the horseradish dip with the fish.
Our tip: Use a deliciously spicy bacon for a delicious touch!