4 ounces cooked lobster meat, cut into 1/4-inch pieces
In a medium bowl, combine the sour cream with 4 tablespoons of the butter, the egg, the chives and 1 teaspoon of pepper. Using your hands, work in the flour. Turn the dough out onto a work surface and knead until smooth and elastic. Shape the dough into two 6-inch disks, wrap in plastic and let rest at room temperature for 30 minutes.
Meanwhile, in a medium saucepan, boil the potato in water to cover until tender, about 20 minutes; drain. Peel and press through a ricer or sieve into a medium bowl. Stir in the remaining 2 tablespoons of butter and the half-and-half, then add the lobster meat. Season with salt and pepper and let cool completely.
On a lightly floured work surface, roll out 1 piece of the dough to a 15-inch round about 1/8 inch thick. Using a 3-inch biscuit cutter or a glass, cut out 12 to 15 rounds. Brush each round lightly with water and spoon 1 scant tablespoon of the lobster filling in the center. Fold the dough over the filling to form half moons, pressing out the air; press and crimp the edges to seal. Arrange the finished pierogi so they don't touch on a baking sheet lined with wax paper. Repeat with the remaining dough and filling.
The pierogi can be refrigerated overnight or frozen for up to 1 month; do not thaw before cooking.