That look is certainly noted, but Ignis at least doesn't say anything right away. Instead, he busies himself about in the rest of the kitchen as he prepares what little else is required for the dish he had in mind. The change in subject is definitely allowed without any protest or attempts to pull it back.

"Hm, that's not surprising. A lot of different types were pulled in. Some have different digestive systems even before dragons became involved, or others can't get sick..."

Or, if they're Ardyn, they're immortal and hate themselves enough to not care about the temporary discomfort...

"But I think I would still prefer cooking in the end. It makes the food far nicer, and that can make yourself and those you care about happier." He looks to her. "Do you like omelets, now that I am thinking on it?"