Grate cheese. Cut the boiled ham into small cubes. Chop chives into rings.
Beat the egg yolks together with Oldenburger Cream in a bowl. Preheat the oven to 220 °C.
Preparing the Pirogies
Spread ham and Oldenburger Cheese mixture onto the dough biscuits. Thinly spread beaten egg yolks round the edges of the biscuits, then fold around the filling and firmly press together the seams. Coat the pierogies with the remainder of the egg cream. Sprinkle with sesame seeds and place on a greased baking sheet.
Bake in a preheated oven at 220 °C for 15-20 minutes until golden brown. Leave to cool on a wire rack.
The Final Touch
Serve as a finger food to accompany drinks.