Small dill sprigs for garnish Place the salmon, lemon juice, dill and mustard in a food processor. Pulse until the salmon is finely chopped. Add the cream cheese and whipping cream and pulse until you create a salmon mixture that is very smooth and light. Season the mousse with salt and pepper.
Arrange cocktail rounds on a platter. Transfer salmon mixture to a piping bag fitted with a star tip. Pipe some salmon mousse on each cocktail round. Chill canapés, uncovered, until mousse is set, and then tent with plastic wrap until ready to serve.
When ready to serve, uncover, garnish each canapé with a small dill sprig, and serve.
Note: Treasure Island brand smoked salmon was used in this recipe. Pumpernickel cocktail rounds are available in the deli department. If unavailable, cut slices of rye bread into rounds or use a sturdy cracker as base for the canapé.