400 gmskinless Spanish mackerel fillets (about 4), halved lengthways and cut into 3cm pieces
1 tbsparbequina extra-virgin olive oil, plus extra for drizzling (see note)
1lemon, juice only
1avocado, flesh cut into 1cm pieces
To serve:chervil sprigs
50 gmspanner crab meat
To serve:Spanish smoked paprika
200 gmwhite sugar
100 mlwhite wine vinegar
½telegraph cucumber, shaved into ribbons with a vegetable peeler
For pickled cucumber, combine all ingredients except cucumber in a saucepan and stir over medium heat until sugar dissolves (3-5 minutes). Bring to the boil, remove from heat, cool, then add cucumber and set aside to cool completely.
Peel grapefruit with a small sharp knife, then segment over a bowl to catch juices. Break segments into small pieces and reserve segments and juice separately.
Place mackerel in a non-reactive dish, drizzle with 1 tbsp each of olive oil, lemon juice and reserved grapefruit juice and 1 tsp sea salt. Toss to combine, then stand until cured (4-5 minutes).
Pile avocado in the centre of four plates. Top each with grapefruit, then mackerel mixture. Scatter with chervil sprigs, drizzle with extra olive oil, if desired, and serve immediately with pickled cucumber, crab meat and paprika to the side.
Note George Sideris sometimes substitutes ruby grapefruit with blood oranges and Valencia oranges, depending on what’s in season. Arbequina olive oil is pressed from arbequina olives grown predominantly in Catalonia. The oil is available from select supermarkets and delicatessens. If unavailable, substitute a good quality extra-virgin olive oil.