Polenta help - undercooked?

[DahliaBloom]

I made a Hugh FW polenta recipe tonight - he specified quick cook polenta but I'm not in UK and nothing like that is available here - I just got cornmeal. Packet said cook 20 mins but I followed recipe (forgetting about the quick cook thing) and just cooked 5 mins before leaving to cool, then cutting up and frying.

Tasted fine and ds ate tons of it. Cooking time discrepancy only occurred to me afterwards. Have never made polenta before - is the length of cooking time a taste issue or food safety?! Can I have made us ill by undercooking?!