Preparation

1. Cook the fish
   Preheat the oven to 200 °C (400 °F).
   Place the hake fillets on a parchment-lined baking sheet and bake for about 20 minutes. Set aside.
2. Grill the bread and onions
   Slice the Belgian bread and grill until nice grill marks appear.
   Grill the green onions 1–2 minutes per side, then roughly chop. Set aside.
3. Prepare the vegetables
   Use a peeler to slice the cucumbers into ribbons.
   Thinly slice the red onion.
   Shred the red cabbage.
   Prepare the arugula.
   Keep everything separate until ready to assemble.
4. Make the radish pickles
   Using a mandoline, slice the radishes.
   In a saucepan, bring the water, sugar, vinegar, and garlic to a boil.
   Remove from heat and let cool for 10 minutes.
   Add the radishes and let marinate for 20–30 minutes. Drain and refrigerate until serving.
5. Make the yogurt sauce
   In a bowl, combine the yogurt, horseradish, and lemon zest. Set aside.
6. Assemble the sandwiches
   Spread the yogurt sauce on the bread slices.
   Top with a hake fillet and a drizzle of lemon juice.
   Add: grilled green onions, cucumber ribbons, red onion, a few pickled radishes, red cabbage, arugula, and bacon (optional).
   Close the sandwich and enjoy!