So first things first, you need to cook the fresh Mackerel fillets. Place the fillets on some baking parchment with a squeeze of lemon, wrap into a parcel and cook in a warm oven for about 5 – 6 minutes. You want the fish to just lose that subtle translucency but not cook through completely. Leave to one side to cool in its parcel while you assemble the other ingredients.
When the mackerel fillets are cool enough to handle place all the ingredients (including the mackerel juices from the parchment parcel) in a bowl and mash up with a fork to break up the fish to create a smoothish texture. You don’t want it to be too smooth but be guided by your own palate and preferences here.
Taste and adjust seasoning with the juice of more lemon and the sea salt.
Serve with some crudities or slices of sourdough toast.