Cabbage with minced meat and porcini mushrooms

Birthdays and family holidays are famous for abundant food and lots of guests. And if an unusual but delicious dish of cabbage with minced meat and porcini mushrooms appears on the table, a full house is provided. What is unusual is that according to the recipe for cooking a dish, the whole head is needed.
You need to prepare a cabbage head: remove the top layer of leaves, leaving only those that fit snugly. Cut out the stalk boldly and cut out the core around it, but carefully so that it turns out to be a hollow vessel.
Finely chop the boiled mushrooms and add them to the minced meat.
Everything that was cut out of the core is crushed and mixed with the finished minced meat. We fill the head with it, tamp it down so that there are no voids. And now remember, we still have the upper cabbage leaves. Here we will cover the minced meat with them, and in order for them to hold, we will tie the head with threads.
We will need cabbage sauce. Fry onions, grated carrots, chopped tomatoes in oil, add a couple of spoonfuls of ketchup and a little water. We take a saucepan the size of the head, pour the sauce into it, add water to hide the head and simmer, closing the lid. Pour the sauce on top periodically.
Cabbage is served whole, then sliced like watermelon slices, poured with sauce.