For a less expensive variation, top the potato halves with 12 ounces flaked hot-smoked salmon instead of caviar.
Place in a saucepan or pot:
Add enough water to the pot to cover by 1 inch.
Bring to a simmer over medium-high heat. Cook, uncovered, just until the potatoes are tender, about 20 minutes. Drain and let cool to room temperature. Cut each potato in half. Using a melon baller, scoop a small crater out of each half and reserve the scooped out potato flesh in a bowl. Cut a thin slice off the rounded side of each half so the potatoes will sit flat. Sprinkle the potatoes with:
Add to the bowl of potato flesh and mix until smooth:
Spoon or pipe the sour cream mixture into the potatoes. Top with:
Sprinkle generously with: