Instructions

1. 1

   Prepare the vegetables and garnish before cooking the fish. Cut off the ends of the cucumber then use a swivelhead peeler to slice from one end to the other, making long ribbons of cucumber like tagliatelle.

   
   

2. 2

   Give the cucumber a quarter turn after you have peeled each length, so that you peel down to the core evenly and get narrow strips.

   
   

3. 3

   Stop when you reach the seeds at the centre and set the ribbons aside in a bowl for now.

   
   

4. 4

   Cut the chilli in half lengthways and remove the seeds, then cut the chilli into a fine dice or strips. Add three-quarters of it to the cucumber ribbons and reserve the remainder.

   
   

5. 5

   Now prepare the spring onions. Trim off the root, pulling away any loose or damaged outer layers. Slice the spring onion on an angle across the width.

   
   

6. 6

   Just before cooking the fish, pick the coriander leaves from their stalks and chop them finely.

   
   

7. 7

   Heat a non-stick frying pan and add a generous film of olive oil. While waiting for the heat to rise, cut the limes in half, squeezing the juice over the cucumber and chilli mix along with two dessertspoons of olive oil.

   
   

8. 8

   Toss well, adding the coriander and half of the spring onion.

   
   

9. 9

   Season the fillets of fish with salt and place them in the pan, skin side down.

   
   

10. 10

    Cook as many fillets at one time as fit comfortably in the pan: if you try to squeeze in too many the heat will be reduced by the quantity of fish, resulting in soggy skin which hasn’t been seared at a sufficiently high temperature.

    
    

11. 11

    Sear the fish on the skin side until crisp, which should take about a minute and a half.

    
    

12. 12

    Squeeze a little lime juice over the fillets then turn them over. Cook the fish for another minute then lift the fillets out on to a plate lined with kitchen paper.

    
    

13. 13

    Arrange the cucumber mix in a long pile across the middle of four serving plates. Place 2 mackerel fillets on each mound then scatter the rest of the spring onion and remaining chilli over the top.

    
    

14. 14

    Spoon any juice left in the bowl of cucumber over the fish then eat at once.