It wasnt the british stealing their food.
It was the british stealing their land. Growing food on it, using them as indentured labour. Then forcing them to live, effectively, on the only crop that could supoort a family on a small plot. That crop just happened to fail.
Interestingly, the reason they had such small plots was that irish inheritance split all the parents possessions equally, dividing the wealth, making smaller plots. The british system, it goes to the eldest, leading to wealth hoarding.