1 blood orange, segmented and juice reserved
1 fennel bulb, core removed and thinly sliced
½ lemon, juice only
1 shallot, finely chopped
1 tbsp chopped fresh tarragon
1 bunch watercress, leaves picked
1 tsp Dijon mustard
1 tsp English mustard
salt and freshly ground black pepper
pinch cayenne pepper
3 tbsp olive oil
450ml/16fl oz fish stock
25g/1oz salted butter
200ml/7fl oz double cream
2 free-range egg yolks, beaten
50²µ/1¾´Ç³ú ³Ò°ù³Ü²âè°ù±ð cheese
6 large raw tiger prawns in shells, cut in half lengthways and deveined
100ml/3½fl oz white wine