How to cook
Preheat the oven to 390°F (200°C).
Wash the fish, remove the entrails and gills, rinse it, dry it and place in a baking tray, lined with parchment paper.
Season the inside with salt and sprinkle it with garlic powder.
Combine the sour cream, mustard, lemon juice, parsley, sea salt and black pepper.
Spread the resulting marinade over the mackerel.
Put butter slices on top and bake for 30-40 minutes, depending on the size of the delicious baked mackerel.
I hope you like this recipe for mackerel with mustard and sour cream.