In a bowl, soften cream cheese and stir in walnuts, chives and celery.
Add 2 teaspoons of lemon juice and spices and mix well. Spread cream cheese mixture on each slice of salmon and season with pepper. Roll up to form neat rolls.
Toast slices of bread and cut 8 (2. 5") rounds, using a biscuit cutter. Spread thinly with butter. Place a cucumber slice on each bread round and place a salmon roll on top of each cucumber. Drizzle with remaining lemon juice and garnish with dill sprigs and chives, if desired.
NOTE: Salmon rolls can be prepared several hours in advance and refrigerated. Toast bases, however, and better freshly made. Once assembled, serve within 30 minutes.