I just inherited a couple of well-seasoned cast iron skillets from my grandmother. I wanted to know if they are good for deep-frying -- i.e. if I wanted to fry tortillas in oil to make tostada shells. My sense tells me it would be fine -- beneficial to the pan in fact, since one conditions a cast iron pan by rubbing it down with oil/fat. But wanted to check with the experts before I ruined a great pan.