Marinated mackerel with beetroot, hazelnuts and horseradish

For the horseradish cream, mix together the double cream, crème fraîche, pepper and a large pinch of salt

Add the horseradish, lemon juice and zest. Whisk the mixture, add the chives and taste to ensure you have the correct seasoning. Place in the fridge to set

For the beetroot dressing, peel and quarter 8 of the beetroot and then juice them in the juicer. This should make 600ml beetroot juice (if you are short, juice more beetroot)

Remove the scum from the top of the beetroot juice, then pass through a fine sieve

Pour the Port into a pan and reduce to 150ml, then add the beetroot juice and reduce until you have 200ml liquid. Leave to cool then add the lemon juice, seasoning and olive oil

Preheat the oven to 170°C/gas mark 3

Wrap the remaining 2 beetroot individually in foil, then bake in the oven for 2 - 2 1/2 hours. Leave to cool in the foil for 15 minutes so that they sweat, then unwrap and rub the skins off. Dice the beetroot into neat 2mm pieces and add to the dressing

Trim the skinned mackerel fillets so they're a clean rectangle shape and season

Toast the hazelnuts in a dry frying pan until golden. Smear the beetroot dressing over the mackerel, then the thyme leaves, and grate over the lemon zest and hazelnuts using a Microplane. Leave the mackerel to marinate for 30 minutes

Preheat the oven to 180ºC/gas mark 4

To prepare the baked beetroot, rub the beetroot in the olive oil, then add 1 tsp of the salt and 1 tsp of the thyme. Wrap in kitchen foil and place onto a wire rack on a tray and cook for 20-30 minutes, depending on size. Once cooked, take out of the oven and leave to cool down on the rack

Remove the foil and peel off the skin. Cut the beetroot into 2mm thick slices, then cut out beetroot rounds with a 2cm cutter

Place the beetroot onto a tray and sprinkle over the dressing, without the bits of diced beetroot. Season with salt and pepper and sprinkle over the remaining thyme

For the pickled beetroot, cut the peeled baby beetroot into quarters, leaving a couple of centimetres of stalk. Peel and quarter the 4 regular beetroot and make another 250ml beetroot juice in the juicer

Simmer the water and add the beetroot juice, vinegar, oil, sugar and salt

Add the lemon juice, thyme, peppercorns, bay leaves and baby beetroot. Cook for approximately 10 minutes, then leave to cool in the liquor

For the beetroot garnish, peel the Cheltenham beetroot, leaving approximately 2.5cm of stalk, then slice them very thinly using a mandoline

Select the best slices with the stalk still intact and place them into iced water so they curl up. Allow 3 per plate

Layer the baked beetroot slices down the centre of the plates, then place the mackerel on top and lay the baby pickled beetroot pieces on top of the mackerel. Quenelle some horseradish cream and arrange on the fish

Scatter the thin slices of Cheltenham beetroot around each plate, then add the baby salad leaves around and on top

Sprinkle some of the beetroot dressing onto the fish and around, then grate over the remaining hazelnuts with a Microplane. Serve immediately