Chicken drumsticks in dough bags

The recipe is widely distributed on the Internet. But there is one know-how for making the bags stable during the baking process.
Required: yeast dough (you can take puff yeast) - 400 - 500 g; chicken drumsticks - 6 pcs.; mushrooms -150-200 g; potatoes - 2 pcs. (medium size); one small onion; some cream for greasing the dough salt, pepper, seasonings.
Preparation:
Boil the potatoes, mashed potatoes (you can add a little butter).
Finely chop the mushrooms and onion, fry in vegetable oil. Mix mashed potatoes and mushrooms.
Salt and pepper the drumsticks, fry until tender for about 25 minutes.
Defrost the dough, roll it out, cut into 8 squares 15x15 cm. From two squares make 6 small circles, which are placed in the middle of the square to strengthen the bottom. Put 1 tbsp in the middle. a spoonful of filling, put the shin. Gather the edges of the dough and tie with culinary thread, being careful not to overtighten.
Grease metal forms for muffins (3.5-4 cm deep) with vegetable oil. Grease dough bags with cream and place in muffin molds (this will give them stability). Wrap the bones in foil to prevent scorching.
Bake in an oven preheated to 180 degrees until golden brown (about 25 minutes). Remove foil and cooking string before serving.