Mackerel with beetroot and horseradish relish

For the fish: stuff the cavity of the mackerel with a handful of parsley and a small knob of butter.

Slash the skin on each side of the fish several times and tuck a thin slice of lemon and a little thyme into each slash. Season the skin with sea salt.

Heat a griddle pan until very hot, and cook the fish for 5-6 minutes on each side, or until the skin is charred and the flesh is cooked through.

For the beetroot: while the fish cooks, heat the vinegar and sugar together in a small pan, until the sugar has dissolved. Turn off the heat, stir in the red beetroot and leave to one side.

Place the golden beetroot in a small bowl and pour over the lemon juice, a drizzle of olive oil, the thyme leaves and seasoning 6. Place a spoonful of red beetroot on a plate, followed by a layer of golden beetroot on top. Place the fish on top of the beetroot.

Mix a little olive oil with any remaining vinegar solution to make a dressing and drizzle over the fish. Finish with a sprinkling of freshly grated horseradish and serve with rye bread.