First place the kindling material at the center of the bottom of the pit, then build the larger wood around it. Place the rocks on top and then light the kindling, as the fire builds, the wood will turn to charcoal and the stones will heat; this takes approximately one and a half to two hours. Once the stones have reached their maximum heat, spread them evenly across the floor of the oven and lay the first layer of vegetation over them. This will create the steam for cooking. Then lay the second layer of ti leaves, which will touch and flavor the food. Place a few hot rocks inside the pig to help the cooking along, and then place the pig and all vegetables in the imu.