Place potatoes in a large saucepan and cover with cold water. Bring to a boil and simmer until just tender but still quite firm, 15 to twenty minutes. Remove all but 6 potatoes. Cook these until soft, about 5 more minutes.
When cool enough to handle, carefully cut off the very tops of the potato. Using a melon ball spoon, scoop out as much potato as possible while leaving at least a 1/4-inch-thick wall remaining. Reserve potato flesh and set aside. Cut a small slice off the bottom of each potato shell so it will stand upright. Place scooped potato in a small metal bowl set over a pan of simmering water to keep warm.
Heat oven to 375 degrees.
Heat the milk and butter in a small saucepan until butter melts. Push the reserved potato flesh and 6 remaining potatoes, peeled, through a ricer or food-mill, into a bowl. Stir in milk and butter a little at a time until creamy. Stir in the crème fraîche, salt and pepper and 1 tablespoon chives.
Place potato mixture in a pastry bag fitted with a large plain tip. Arrange the potato shells on a baking sheet. Pipe filling into the shells, making sure to cover cut edges.
Bake for 15 minutes or until golden brown and slightly puffed. Brush with melted butter and bake for 15 minutes more.
Top each potato with a spoonful of caviar and sprinkle with chives.
32 small red potatoes (about 3/4 pound)
1/2 cup plus 2 tablespoons milk
1 tablespoon butter, plus 2 tablespoons more for brushing
1/4 cup crème fraîche
Salt and freshly ground pepper
1 tablespoon fresh chives, plus more for garnish
3 ounces White Sturgeon caviar or Siberian Sturgeon caviar (about 1/4 teaspoon per potato)