To be clear about the history, there was plenty of food produced by the Irish - it was taken by the British as taxes.
Yes there was a catastrophic failure of the potato crop. It was still a manmade colonialist failure though - the poor survived on potato because the beef, wheat, and butter were being sent to Britain. Irish catholics were tenant farmers.
To make things worse, as the potato crops failed due to the blight, grain exports continued. The British put additional policies making things even worse, and while there was food, many people in Ireland just couldn't afford it.
Once again, capitalism/colonialism is to blame for famine, while the British shifted blame to the potato blight that wasn't remotely the real cause for the famine.
