Preheat oven to 350℉. Cut tops from bell peppers and set aside. Remove interior membrane and seeds to shape the peppers into cups. Gently break stems away from pepper tops, dispose of stems, then dice remaining pepper tops and onion.

Add diced onion and bell pepper tops to a frying pan and cook until onion starts to turn translucent, then add jalapeño and ground beef and cook until browned. Season with salt, black pepper, and cayenne (optional), to taste. 

Create filling by combining ground beef mixture with cooked rice, salsa, beans, and 5 ounces cheese, then scoop filling into pepper cups and pressing down on mixture to remove any air pockets. Place pepper cups into a baking dish, loosely tent with foil, and place in oven for 30-45 minutes. (A shorter cook time results in crunchier pepper texture.) When done, remove foil, garnish peppers with remaining shredded cheese, and return to oven for 15 minutes. Remove from oven and let rest for 15 minutes before garnishing with cilantro and serving.