Giancana had gallbladder surgery in Texas ( Dr. Michael DeBakey) and probably could not eat spicy foods. He most likely had heart problems as well. These guys didn't take good care of themselves.
Good point. In addition to a ban on spicy foods, Sam probably had doctor's orders for eliminating fatty meats, cheese, and smoking, also. Like many hedonistic mobsters, Sam probably ignored the doctor. So, I can imagine Giancana cooking up the late night snack for himself.