Line a terrine with cling film. Line the base and sides with 3/4 of the smoked salmon.
In a large pan over medium heat, add the spinach and cook until it is wilted, about 3 minutes. (You may need to do this in batches.) Set aside to cool.
When cool enough to handle, squeeze as much water out of the spinach as possible and then finely chop it along with the small knob of butter and some freshly ground black pepper. Spread out evenly on a chopping board to be the same size as the terrine mould (use the lid as a guide). Allow to cool completely.
In a bowl, combine the flaked salmon, chopped prawns, lemon juice, lemon zest, cayenne pepper, thyme and salt.
Prepare the gelatine according to the packet's instructions.
In another bowl, lightly whip the cream, then fold in the salmon mixture. Fold in the prepared gelatine.
Pour half of the mixture into the terrine. Top with the spinach mixture. Gently spoon the remaining salmon mixutre over the spinach.
Fold over any of the smoked salmon slices that stick up; finally completely cover with the rest of the smoked salmon slices.
Place the lid on the terrine and chill in the fridge for a minimum of 8 hours, or up to 2 days.
To serve, loosen round the edges, and invert the terrine onto a serving platter. Cut finger-width slices, 1 or 2 per person. Watercress and lemon garnish is great!
Instead of salmon, any fish that can be flaked after cooking will do, but it should be compatible with the fish used for wrapping the terrine. You can use smoked trout instead of smoked salmon to line the terrine.
I have made this twice now and yes it does take a little while to make but oh my was so pleased with the way it turned out both times and tastes delicious . Be brave and have a go it really is worth it! - 26 Jun 2013