Make the Dough: Scald the Milk, remove from the heat and stir in the butter. Allow to cool to about body temperature, below 120 degrees. While that is heating and cooling, put yeast and sugar in warm water. Mix until it dissolves. Let it bloom for about 10 minutes until it becomes frothy.
Use a mixer with dough hook or mix the dough bu hand in a mixing bowl by adding the yeast to the milk and butter, and fold in the flour. Knead until a firm dough forms. Add more flour if it is too wet. Coat the dough with oil, cover with plastic and allow to rise for about 30 minutes.
While the dough is rising make the filling: Saute Onion and garlic in a light coating of oil until translucent. Add in the meat and break it apart. Cook it through. Add in the cabbage and cook until it is just softened.. Add in the cheese and herbs and remove from the heat. Stir well until the cheese melts and the filling becomes scoopable. Set aside.
Make The Sauce: Saute the Shallots in a small amount of oil or butter until translucent. Add in the mushrooms and cook until soft, stirring as needed. Add the wine and cook down until it has almost all evaporated. Add the Demi glace and cook down until it coats the back of a spoon. Stir in the sour cream, season with salt and pepper, and add the herbs.
Remove the dough from the pan. knead it in flour for a couple turns. Roll out the dough to less than 1/4 inch thick. Do it in workable pieces. Cut out 3 inch circles of dough. Put a generous amount of filling into the center of each circle. Dip fingers in water and close the dough up by pinching the folds together. You should end up with oblong dumplings. Make sure the dough is well cinched so the filling doesn't leak out.
Heat 2 inches of oil in a heavy pan over medium high heat. Fry the dough until golden brown. Flip sides to cook evenly. Alternatively, you can cook them in a pan with very little oil to get a crisp browning on either side. Then, pop them into a preheated 400 degree oven for about 5 to 10 minutes to finish cooking them all the way through. Serve with the mushroom sauce.
