Sorry Shreck,
Take no offense I just did not have the time to reply right away.
It's similar to all the other replies.
They dig a hole about three to four feet deep, and put the rocks in. Then they heat it up really hot with hard wood.(Mesquite) Then they prepare the pig with rock salt and they wrap it up with chicken wire.(They burn the galvanizing off first).
We use banana stumps slit in half, banana leaves and Ti leaves. A lot has to be used to fully cover everything and it has to be done quickly before the pig gets burned. Then we use wet burlap bags to cover everything up also.
Then you have to use a very thick canvas to cover up the burlaps.
After that you have to cover the edges of the canvas to seal the heat in. If steam is purging out, you have to put more dirt to weigh it down otherwise flames will be shooting out and the burlap will dry out and burn. In the earlier years, they did not use the canvas or burlap bags and they covered the entire pit with the banana leaves then covered with dirt. But now since we use the burlap and the canvas, it is easier to uncover and there is a lot less mess.
After ten to twelve hours, you pull it out by grabbing on to the chicken wire because it will be super hot and the meat will be falling off the bone! Some of the pigs that they cook weigh up to 700 lbs!(before gutting)
I am not sure what kind of leaf you can use in replacement of banana stumps and leaves because they have a lot of moisture in them. That is how the pork gets steamed and not burnt.
Remember, it is very important to keep a good seal around the canvas. It's like one big pressure cooker!
In Hawaiian, it's called an "Imu"
Aloha,
Heeman