Procedure

Take the foil and make a long rope of foil.

Roll foil to make a ring( the cabbage sits on the ring to stabilize)

Carefully core the root end to create a cone shape inside.

Pack the mushrooms and onions inside the cabbage.

Top with the butter and season.

Grill or roast till the cabbage is some what soft to the touch.

Remove some of the outer leaves that have charred.

Place in a bowl and quarter and let it fall