Thaw the frozen mackerel fish.
Season the fish with the salt and black pepper. Spread the seasoning evenly on both sides.
Put the parchment paper on the baking tray and spread one layer of oil onto the parchment paper.
Put the fish on the parchment paper and let it rest for 15 minutes.
Preheat the oven to 200°C for 15 minutes.
Grill the fish for 20 minutes in the oven.
Done and serve immediately.