In a large bowl, mix together 2 cups of flour, sugar, yeast, and salt.
Heat the milk, 6 tablespoons of butter, potato flakes, and water in a saucepan until the temperature reaches 120°-130°F. Pour this mixture into the dry ingredients and beat until just combined.
Add the egg to the mixture and beat until the dough becomes smooth. Gradually stir in the remaining flour until a stiff dough forms.
Knead the dough on a floured surface for about 6-8 minutes until it becomes smooth and elastic. Place the dough in a greased bowl, turning it once to coat the top. Cover the bowl and let the dough rise in a warm place for about 1 hour or until doubled in size.
To prepare the filling, whisk together the egg, cream, and salt in a heavy saucepan. Cook the mixture over low heat, stirring constantly, until it thickens. Remove from heat and stir in the chives. Allow the filling to cool.
Punch down the risen dough and divide it in half. Roll out one portion into a 16x12-inch rectangle. Spread half of the cooled filling over the dough, leaving a 1/2-inch border around the edges.
Roll up the dough jelly-roll style, starting from a short side. Pinch the seam to seal. Place the roll seam-side down on a greased baking sheet and pinch the ends together to form a ring.
Using scissors, make cuts from the outside edge of the ring to two-thirds of the way toward the center at 1-inch intervals. Gently separate the strips and twist them to expose the filling.
Melt the remaining butter and brush it over the ring. Sprinkle with sesame or poppy seeds.
Repeat the process with the remaining dough and filling.
Cover the rings and let them rise in a warm place for about 45 minutes or until doubled in size.
Preheat the oven to 350°F. Bake the rings for 20-25 minutes or until lightly browned.
Remove the rings from the baking sheets and place them on wire racks to cool before serving.