Line a terrine mold with plastic film. Cook potatoes in well salted water, or in chicken stock. Cool slightly, peel and chop coarsely. Then, let them cool thoroughly.
Mix in cream, chives, and black peppercorns, salt to taste.
Starting and ending with the potato mixture, alternate layers of the potato mixture and the smoked salmon.
Cover with plastic film and place a weight on top (about 5 pounds) and chill for 3 hours or more.
Invert onto cutting board. Using electric knife or slicer, cut into 1/4 -1/2 inch slices.
Serve with sauce of your choice (e.g. sauce grebiche, sauce aurore, creamy Roquefort vinaigrette).