Maybe this is the moment he gets smart and by mistake he throws the whole sacred-blood beast inside. After eating he realizes that he gained twice the points he should and realizes he threw the stone when he put the beast inside the pot...
Or something like that.
"Han Sen sat up, his eyes falling on the shreeky beast he was feeding. Its fur was dark and shiny like black jade."
Didn't he say the shreeky beast got no fur and he can cook it right away?