1. Place the mackerel fillets into the cucumber and summer cup brine for 30 minutes. 2. Then drain the fillets. 3. Cut them down the middle so you have 8 belly fillets and 8 ‘royal’ fillets.

This simple mackerel and potato salad is perfect when you fancy something a little different for supper. Making your own dressing makes it extra special. Fresh mackerel is usually sold whole with ...