Wash and drain the chicken thoroughly. Clean, wash and roughly cut the soup greens into pieces. Peel and quarter 1 onion. Put the chicken, soup vegetables, onion, bay leaves, peppercorns and some salt in a large pot.
Add 2-2 1/2 litres of water, bring to the boil, cover and simmer over a low to medium heat for 1-1 1/4 hours. Put rice into 400 ml boiling salted water, cover and let it swell for about 20 minutes at low heat.
Let the rice cool down. Boil 5 eggs hard, quench under cold water, peel and let them cool down. Lift the chicken out of the broth, drain and let it cool down a bit. Pour chicken stock through a sieve and measure 3/8 litres.
Knead 400 g flour, 200 g room-warm butter, 1 pinch of salt, rum and 6-7 tbsp. cold water to a smooth shortcrust pastry. Wrap in foil and chill for about 30 minutes. Peel and finely dice 1 onion.
Clean, clean and slice the mushrooms. Heat 15 g butter in a frying pan, fry the mushrooms and half of the onion cubes. Season with salt and pepper and put aside.
Wash the herbs, shake dry and set aside some dill for garnishing. Chop the herbs separately. Dice eggs. Melt 35 g butter and mix with eggs and dill. Remove chicken meat from bones and skin and cut into pieces.
Heat 50 g butter in a saucepan, fry the remaining onion cubes in it. Add 50 g flour, sauté and add the measured chicken stock and 125 g cream, stirring continuously. Bring to the boil and simmer for 4-5 minutes while stirring.
Add parsley to the sauce and season with salt and pepper. Mix 1/4 of the sauce with the mushrooms, add the chicken meat to the rest of the sauce. Cut off about 1/3 of the short pastry and roll out on baking paper to a round plate (30-32 cm Ø).
Put the baking parchment on a baking tray and place a closed springform pan rim (a 26 cm Ø pan) in the middle of the dough. Layer the ingredients in the form in the following order: rice, egg mixture, chicken meat and mushrooms.
Repeat this in the same order. The individual layers must become smaller towards the top to create a dome / hemisphere. Remove the edge of the springform pan. Separate 1 egg. Coat the edges with egg white.
Roll out the remaining dough on a floured work surface to a round plate (approx. 45 cm Ø) and place it over the filling. Press the edges of the dough well together and, except for a 1-2 cm wide edge, cut off all around with a small wheel.
If necessary, use a round spoon handle to press a pattern into the edge of the dough. Use a small cookie cutter to cut a small hole (chimney) in the middle of the dome. Knead the dough remains together, cut out flowers (5-6 cm Ø) as desired, brush with egg white and decorate the pirogi with it.
Mix the egg yolks with 1 teaspoon of cream. Spread the pirogi with it. Bake in the preheated oven, lower shelf (electric oven: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 40 minutes. Garnish with dill if necessary and serve warm.