- 140ml/4½fl oz white wine vinegar
- 140ml/4½fl oz dry white wine
- 1 piece lemon rind
- 1 star anise
- 1 tbsp sea salt
- 6 peppercorns
- 2 good-sized mackerel, filleted and pin-boned
- 1 tbsp oil
- 30g/1oz butter
- 55g/2oz butter
- 450g/1lb rhubarb, half roughly chopped and half cut into 2.5cm/1in batons
- 110g/4oz caster sugar
- 2.5cm/1in root ginger, peeled and crushed
- splash of grenadine
- ½ lemon, juice only
- 1 tsp chopped fresh parsley
- 1 tsp fennel seeds
- For the mackerel, put the vinegar, wine, lemon rind, star anise, salt and peppercorns in a pan and bring to the boil. Pour into a tray and lay the mackerel fillets in the liquid skin-side up. Leave to cool.
- For the rhubarb, melt the butter with the sugar in a clean pan. Add the ginger and roughly chopped rhubarb. Cook gently until it becomes a purée, then break it up using a wooden spoon. Add the grenadine and rhubarb batons. Cook gently, keeping the batons whole.
- Meanwhile, take the mackerel fillets out of the liquid and carefully dry. Heat the oil in a frying pan, add the mackerel, skin-side up, and cook for approximately five minutes. Meanwhile, add 30g/1oz butter and continually baste the mackerel with this.
- In a clean pan make the sauce. Heat the butter until it starts to turn golden-brown. Remove from the heat and add the lemon juice, parsley and fennel seeds.
- To serve, lay the rhubarb in the middle of serving plates. Carefully lay the mackerel on top. Spoon the sauce over and serve.