Looking at the link, I don’t see it actually saying she ate curry. Just that someone gave her some Indians who were able to make curry and that it was on the weekly menu. Not sure if they meant it as options or not. Perhaps I was wrong though and just remembered something from The Supersizers. Giles mentioned that in the narration once, though he also said during the Medieval episode people used spices to cover the taste of rotting meat. Eurasian spices cannot cover the taste, it would be unhealthy to eat that, the spices were more expensive than meat, plus they tended to butcher animals around the time they were going to eat them. Still, these things sink into the common knowledge. We also would need to consider whether the version eaten in Britain at the time would be as different from the many cuisines in Indi as Mexican and Chinese food in America is.