Mackerel with cucumber and borage

4
35 minutes

Ingredients

Mackerel

  • 2 mackerel, boned and filleted with the belly reserved (ask your fishmonger)
  • 2 tbsp of creamed horseradish
  • 1 tbsp of dill, chopped
  • sea salt
  • rapeseed oil, for frying

pickled cucumber

  • 1 cucumber
  • 300ml of water
  • 200g of white vinegar
  • 100g of salt
  • 100g of sugar
  • 1 tbsp of juniper berries, peppercorns, coriander seeds and star anise (all mixed together)
  • 50g of dill, chopped

roasted cucumber and sauce

  • 2 cucumbers
  • sea salt
  • 12g of ultratex, or 3g agar agar

to serve

  • borage flowers

Method

1
Begin by preparing the pickled cucumber, as this can be done well in advance. This will make more than you need for this dish, but it will last for a few weeks in a sealed jar. Place the water, vinegar, salt, sugar and mixed spices into a saucepan and heat gently until the sugar and salt dissolves. Set aside to cool slightly
2
Meanwhile, finely sliced the cucumber and pack it into a sterilised Kilner jar. Once the liquor has cooled a little, stir in the dill, then pour the contents of the pan into the jar with the cucumbers, ensuring they are completely submerged. Seal, give the jar a shake, then leave to pickle for at least a few hours
3
For the roasted cucumber and cucumber sauce, top, tail and peel 1 of the cucumbers, reserving all the trimmings and peel for the sauce. Roughly chop the remaining cucumber, then place it in a juicer along with the reserved trimmings and peel to create approx. 240ml of cucumber juice
4
Transfer the juice to a blender, then stir in a teaspoon of salt and a tablespoon of the pickling liquor from the pickled cucumbers. Begin blitzing on low, then with the motor still running add the ultratex. Slowly increase the speed until a vortex forms in the blender – the sauce will begin to thicken from the bottom, so make sure you keep blending until it is thickened throughout. If using the agar agar, combine with the juice and gently warm, then leave to set in the fridge before blitzing
5
For the mackerel, finely chop the reserved belly and mix with the creamed horseradish and dill. Season and set aside
6
Salt the mackerel fillets lightly, brush with a little rapeseed oil and set aside until ready to cook
7
Take the peeled cucumber and cut in half, then cut the halves into 2 pieces – you should be left with 4 equal pieces. Lightly salt the exposed flat sides of the cucumber with a little salt and sear in a hot pan until well charred
8
Once cooked, set the seared cucumber aside and add the mackerel fillets, skin-side down. Cook until the skin crisps – there’s no need to turn the fish as the residual heat will cook the fillets completely
9
To serve, place a piece of roasted cucumber and a mackerel on each plate. Add a spoonful of the horseradish and mackerel belly, along with a few slices of pickled cucumber. Pour over the cucumber sauce, then garnish with dill sprigs and borage flowers