Halve potatoes; cut and discard a very thin slice from skin side of each half.
In 2-quart saucepan, cover potatoes with water; add salt. Bring to boiling over high heat, reduce heat, cover and cook until tender, 10 to 15 minutes, depending on size of potatoes.
Drain; cool to room temperature. Meanwhile, in small bowl, mix cheese, salmon, lemon juice and pepper to blend thoroughly.
With small spoon, mound salmon mixture onto potato halves and cucumber slices, dividing equally (1 to 1 ½ teaspoons each).
Arrange on serving plate and add your choice of garnishes. (If not served immediately, these can be prepared several hours in advance; cover and refrigerate. For best flavor, return to room temperature just before serving.)