When the parboiled maize gets cold, you grind it after which you mixes it with little oil and keep. If you are using agbugbu or akidi elu or oralu di as the case may be, you cook until it softens.
If there is bitter leaf which is always advisable to use, add it and drop a little oil to avoid water rising and entering the maize.
Put your locally made basket; turn it upside down, and put the grinded maize on top.
After few minutes, use your turning stick to turn it in such a way that the one under will come up and cover the pot.
Cook until it tastes somehow dry, showing you that it is done. In my own case, I do cook it for up to 45 minutes or more. By then, the agbugbu or whatever beans you are using might have done, bring the pot down.