Cut the chicken by removing the bones from it.
Salt, pepper and spice the chicken on both sides. Leave the chicken to lie down a bit and do the filling.
Boil rice by taking two parts of water to one part of rice. Fry the chopped onion in a frying pan in vegetable oil, when the onion is browned, add the mushrooms to it, pour the liquid from them in advance, mix. In a separate cup mix all the ingredients - minced meat, rice and fried onion with mushrooms, salt and pepper the filling. Stuff the chicken with minced meat fastening the edges with wooden sticks. Coat with mayonnaise, put on a sheet and put in an oven preheated for 180ºC for 2 hours.