gwai fēi gāi
貴妃 is the title of a high-ranking imperial concubine, in this case referring to the famous (or infamous) Yang Gui Feng, and 雞 is chicken.
Gui fei chicken is a Cantonese dish similar to Hainan chicken but with the chicken soaked in different flavors. It's also known as Empress chicken (it was allegedly a favorite dish of a famous concubine who ruled as an Empress), although that name is also applied to stir-fried chicken wings.