2 medium cucumbers, peeled
50g/1戮oz fresh dill, finely chopped
5 tbsp Dijon mustard
salt and freshly ground black pepper
plain flour, for dusting
2 tbsp clear honey
1 tbsp white wine vinegar
1 free-range egg, beaten, combined with a little milk
1 x 380g/13oz ready-made puff pastry sheet
1 x 2.8kg/6lb salmon, skin removed and filleted into 2 pieces