1 large cucumber, peeled and very finely sliced
1 lemon, juice only, plus extra lemon wedges to serve
50驳/1戮辞锄 watercress leaves
sea salt and freshly ground black pepper
1 tsp rapeseed oil, for greasing
200g/7oz full-fat cream cheese
450ml/16fl oz double cream
300g/10陆oz cooked tiger prawns, shells removed, de-veined, plus 6 extra tiger prawns, shells left on
400g/14oz smoked salmon fillet (unsliced), chopped