What men like to cook would be איזה גברים אוהבים לבשל? unless I got my English wrong.
So איזה has more than one meaning? I thought מה is always what and איזה is always which.
You're generally right, but in this case, I understand the sentence "What men like to cook" as having the same meaning as "Which/what sort of men like to cook". I may be wrong... but if there is an irregularity in this case it is in English.