Sauté the diced onions in 3 tablespoons of olive oil until translucent, deglaze with the stock of the pickled cucumbers and 750 ml of stock. Add the diced pickles, the letscho, the roughly chopped tomatoes and the capers. Bring everything to the boil briefly and season with salt, pepper and rose paprika to taste. Don`t forget a pinch of sugar!
Cut the fish fillet into bite-sized pieces and leave to stand in the stock for 12-15 minutes. If necessary, add salt again. Serve with lemon wedges and sour cream.