Remove the husk from the corn.
Remove the corn kernels from the cob.
Peel the onion and cut into quarters.
Add the corn and onion into a food processor; and blend coarsely with as little water as possible. I used about a quarter cup.
Pour the ground corn into a bowl and add the cornflour.
Add the palm oil and some salt to taste, then mix in the spinach.
Line a pot with the husk of the corn, so the husk covers the base as much as possible. This is to prevent water from getting into the wrapped foil.
Pour water into the pot, so it nearly covers the corn husk. Place a piece of aluminium foil over the husk. Place under low heat while you wrap the ground mixture.
Cut a piece of aluminium foil and scoop the mixture into it. Gently wrap the foil around the mixture and fold over the edges.
Place the wrapped bundles in the pot. Fold the aluminium foil over or use another piece to cover.
Allow to steam for around 1hr. Check after 15-20 mins to make sure the water has not dried out totally as the husk will start to burn if this happens. If needed, add more water closer to the edge of the pot to avoid getting the wraps wet.
Remove from heat and allow to rest for 10 mins before eating.