Preheat the oven to 200 degrees Celsius.

Season the cod fillets with salt and pepper.

Cut the celery into thin rings.

Grab a baking paper and place it in front of you.

Spoon 2 tablespoons celery on the paper.

Top with the fish and cover the fish with cherry tomatoes, some slices of shallot, a piece of mozzarella and basil.

Grate some Parmesan cheese and fold the package so it's closed.

Tie with kitchen twine.

Repeat for each cod fillet and place the packets on a baking sheet.

Put the baking sheet in the oven and bake the fish until done in 20 minutes.

Open packets carefully (there can come true steam) and sprinkle a little more parsley on top.