- 4 medium mackerel, butterflied, pin bones removed
- salt and freshly ground black pepper
- 4 good-quality pork sausages, filling squeezed out, skins discarded
- 1 bunch fresh tarragon, chopped
- 1 bunch fresh flatleaf parsley, chopped
- 500g/1lb 2oz all-butter puff pastry
- 2 free-range egg yolks, beaten
- ½ cucumber, peeled, halved lengthways, seeds scooped out, sliced
- pinch sugar
- 2 tbsp cider vinegar
- ½ tsp salt
- 2 bunches watercress
- 1 tbsp olive oil
- squeeze lemon juice
- Preheat the oven to 200C/400F/Gas 6.
- Season the mackerel with salt and freshly ground black pepper.
- Mix the sausagemeat, tarragon and half of the parsley together in a bowl.
- Spread the mixture over the cut side of the mackerel, then fold each mackerel in half along the spine. Chill in the fridge.
- Meanwhile, cut the puff pastry into four pieces and roll each piece out to a 5mm/¼in thickness.
- Wrap each fish in a piece of pastry, leaving the mackerel tail poking out, trim any excess and crimp the edge like a pasty.
- Brush the top of the pasties with the beaten egg and bake in the oven for 25-30 minutes, or until the pastry is cooked through and golden-brown.
- Mix the cucumber, sugar, vinegar and salt together in a bowl and set aside for five minutes, stir in the remaining parsley.
- To serve, toss the watercress with the olive oil and squeeze of lemon juice. Serve the pasties with the watercress and cucumber salad alongside.