Mix flour, salt and sugar, mix and then add yeast. Add the butter, egg, milk and cumin. Mix until smooth, cover and let rest for 1 hour at room temperature to rise. Mix duck, plums, walnuts and remaining ingredients place on stove and simmer for 3 minutes. Season with salt and pepper. Let cool. Roll out dough to 1/8-inch thick and cut into 3-inch circles. Place 1 teaspoon of mixture in the center of each circle, fold over and crimp edges. Bake in a preheated 350 degree oven for 10 minutes until golden brown. Serve with sour cream and grilled apples.