Yeah it's relatively easy with the right equipment. Get two pots matching pots, put a little bit of water in the bottom of one. In the other get some bones (usually free from the butcher I used cattle bones) put mesh over it. Place this pot inverted on the pot with water and then seal lip really well with clay. Dig hole in ground place your two pots in the ground and have a fire on the top for a few hours. All going well you will have some bone sauce.

Might take you a couple of tries but it's fairly easy to do.