1. Let the cream cheese soften at room temperature so it blends smoothly.

2. Add cream cheese, sour cream, lemon juice, lemon zest, Dijon mustard, horseradish, black pepper, and a small pinch of salt to a food processor.

3. Blend until the mixture is smooth, stopping once to scrape down the sides.

4. Add most of the smoked salmon, saving a few pieces for garnish.

5. Pulse until the salmon is blended into the creamy base, leaving it slightly textured or fully smooth depending on your preference.

6. Transfer the mousse to a bowl and fold in the chopped dill and chives.

7. Cover and refrigerate for at least 1 hour so the mousse firms and the flavors blend.

8. Spoon into a serving bowl, swirl the top, and garnish with reserved smoked salmon, dill, capers, lemon zest, or cracked black pepper.

9. Serve chilled with crackers, cucumber slices, toasted baguette, or endive leaves.