"Stuffed jalapenos" refers to jalapeno peppers that have been cut open, filled with a tasty mixture (such as cheese, meat, or spices), and then cooked or baked. Full definition
Serve a delicious snack with Calmex stuffed jalapeno Peppers with Sardines Filling, so delicious your guests won't know the sardines came from a can. (mexgrocer.com)