Preheat the oven to 390 °F. Cut the potatoes into thick slices and parboil them briefly.

Rinse the leeks and cut them into diagonal pieces. Slice the onions into half rings and cut the cod into pieces.

Heat the olive oil in a wok and briefly stir-fry the leek and onion. Season with pepper and, if desired, salt.

Divide the vegetables over pieces of baking paper and place the cod on top. Spread the fish with the herbed cream cheese and fold the parcels closed.

Place the parcels on a baking tray and bake them in the middle of the oven for 20 minutes until cooked through.

Meanwhile, fry the parboiled potatoes in the remaining olive oil until golden brown. Serve the fish parcels with the fried potatoes.