"We dug the hole pretty deep, then we got all the wood and rocks and came and stacked them up," said Joseph.
The school's board of trustees supplied the meat and the female pupils prepared the trays of food.
Maori custom says only males can put the hangi down [into the earth].
Ms Hawkins said preparing the hangi took a lot work, from collecting the stones to digging the hole.
It's a good team-building exercise, she said.
"It's really good to do the hangi together, as a whanau."
The hangi was planned for Matariki, the Maori New Year, but strong winds meant the school had to postpone it.
"Today is the perfect day for it," said Ms Hawkins.
The pupils also planted trees after the hangi.