Wash the bell peppers and pat dry. Using a sharp knife, remove the top and the core of the bell peppers. You can do that by placing the knife upside-down along the sides of the cap and cut in a circular motion.
In a bowl, add leftover cooked rice, chopped white onions, minced garlic, leftover meat, chili flakes, scallions, cheese, salt, and mix well using your hands until all the ingredients are well combined.
Scoop in the prepared filling, equally, into each of the bell peppers.
Top them up with more shredded cheese and chopped scallions.
Place these bell peppers on a parchment-lined baking tray.
Place the baking tray in a preheated oven at 400 degrees F for about 40 to 45 minutes.
Once the cheese gets a golden color, remove the baking tray from the oven.
Serve the bell peppers hot. Enjoy!