
These cucumber canapes are a fresh, elegant appetizer topped with a creamy smoked salmon mousse. They are easy to make ahead, look impressive on a platter, and are perfect for holidays, brunches, or cocktail parties.
Make the smoked salmon mousse: add the smoked salmon, cream cheese, sour cream, mayonnaise, chopped fresh dill, garlic, lemon zest, lemon juice, and salt and pepper to a food processor.
Blend until the mixture is completely smooth and creamy, stopping to scrape down the sides as needed so everything is evenly incorporated.
Transfer the mousse to a piping bag fitted with a large star tip. Refrigerate for about 5 hours, or until firm enough to pipe neatly.
Prepare the cucumbers by slicing them into rounds about 1.5 cm (about 1/2 inch) thick. Use a small melon baller or teaspoon to scoop a shallow well from the center of each slice, leaving the base intact.
Pipe the chilled smoked salmon mousse into the cucumber cups. Garnish with extra dill sprigs and lemon slices if desired, then serve immediately.
For the cleanest presentation, pat the cucumber slices dry before piping. If you do not have a piping bag, spoon the mousse into the cucumber cups. The mousse can be made 1 day ahead and kept refrigerated, but assemble the canapes shortly before serving so the cucumbers stay crisp.