How to Make It
Preheat the oven to 400°. On a large rimmed baking sheet, toss the potatoes with the oil; season with salt and pepper. Arrange the potatoes cut-side down and bake for about 25 minutes, until tender and browned on the bottom. Let cool to warm.
Meanwhile, roll out the caviar between 2 sheets of plastic wrap to a 5-by-6-inch rectangle about 1/8 inch thick. Cut the sheet into 20 diamonds or rectangles.
Transfer the potatoes to a platter cut sides up and dollop sour cream on each. Top with the caviar diamonds and garnish with the chives. Serve right away.