And in order to have a perfect drum, to cover it all with jelly - you will have to put some weight on it until it cools down.
I put a cake pan, the same size as the one in which I made the drum - and I loaded it with everything I had harder in the kitchen (but do not put more than 2kg, it will press too hard and the juice will come out completely from the pieces of meat, so the drum will be too dry). I made the drum in the evening and left it overnight, so pressed, until it cooled completely.