Preheat your oven to 420 degrees Fahrenheit (220 degrees Celsius).

Combine all the seasoning ingredients in a small bowl and mix well.

In an oven-safe pan lined with Gefen Parchment Paper, place the cod fillets.

Spread the seasoning mixture evenly over the fish.

Layer the sliced onions and tomatoes on top.

Sprinkle the capers over everything.

Cover with wet parchment paper and bake for 20 minutes.

Remove the cover, switch the oven to convection broil at 450 degrees Fahrenheit, and broil for 10 minutes until the tomatoes begin to crisp.

Garnish with flaky salt, parsley, and chives.