Line 8 small dariole moulds with cling film. Line each one with a layer of the smoked salmon, ensuring the salmon pieces come up to the top of the moulds. Chill in the fridge until needed.
Meanwhile, mix together the soft cheese, the juice from 1 lemon and the snipped chives. Fill the dariole moulds with the soft cheese mixture, put the avocado slices on top, fold over the excess salmon and chill in the fridge for at least 1 hour before serving. Turn the parcels out onto small side plates to serve.
For the Melba toast, preheat the grill to high, cut out 8 stars from the bread using the cutters and toast lightly for 30 seconds to 1 minute on each side. Slide a knife between the toasted edges to split each star, so you have 16 in total.
Place the untoasted sides facing upwards and toast under the grill for a further 30 seconds to 1 minute, until golden and the edges curl. Cut the remaining lemon into wedges and serve with the salmon parcels and Melba toast. Garnish the dish with the reserved whole chives.