First line the base and sides of each ramekin with cling film making sure you have a little surplus over the edges - this helps get the terrine out when set. Then line the base and sides of the ramekins with slices of smoked salmon, again leaving a little surplus over the edges.
For the filling: whisk together the the crème fraiche, cream cheese, mustard, horseradish, lime, capers, pickled cucumbers, ketchup, and parsley in a mixing bowl with a pinch of salt and pepper until smooth
Fill each ramekin half full with the filling mixture, then top with two prawns. Pile the remaining filling on top, just until it almost reaches the top of the ramekins, then fold the surplus salmon over the top to completely conceal the terrine. Fold the cling over the top and gently compact, then chill for at least two hours.
Turn out of the moulds, remove the cling film and serve garnished with a sprig of fresh dill on top