Butterflied Mackerel and Cavolo Nero with Garlic & Herb Butter

2 whole mackerel, butterflied and pin-boned (about 600–700 g total)

90g All Things Butter Garlic & Herb Butter, cubed & cold

1 tbsp neutral oil

Fine sea salt and black pepper

1 lemon, for zest

120ml dry white wine

1 tbsp water

2 tbsp lemon juice

200g cavolo nero, ribs removed, leaves torn

20g All Things Butter Salted Butter

Step 1

Boil wine and water to about 2 tbsp on high heat. Take off the heat for 15 seconds. 

Step 2

Return to low heat and whisk in the cold butter a few cubes at a time until smooth and glossy. Whisk in lemon juice, salt and white pepper. Set aside and keep warm, but do not simmer.

Step 3

Blanch the cavolo nero leaves in salted boiling water for 45-60 seconds and drain well.

Step 4

In a pan, melt the salted butter, and add the cavolo nero, lemon zest, lemon juice and a pinch of salt. Toss for 1-2 minutes until glossy. Keep warm.

Step 5

Meanwhile, lightly score the skin of the mackerel  in a 1 cm crosshatch. Pat very dry and season with salt & pepper. 

Step 6

Heat a wide pan with a dash of oil until very hot. Sear skin-side down for 3-5 minutes until well coloured and almost cooked through. Flip for 20-40 seconds, then take off the heat and grate over a little lemon zest.

Step 7

Plate up the cavolo nero on warm plates, place the mackerel on top, and spoon the buttery sauce over the dish. Serve immediately and enjoy!