Arrange the prepared bell peppers in a 9"x13" baking dish.
Heat a skillet on med-high heat. Add the olive oil and onion. Cook until onion is tender.
Add the ground beef or turkey and cook, stirring and breaking up the chunks, until the meat is mostly cooked.
Add 1 tsp of the salt, ½ tsp of the pepper, 1 tsp of the garlic powder, the onion powder, paprika, and 1 tsp of the Italian seasoning. Stir well and continue cooking until the meat is cooked through.
Take the meat mixture off the heat and add the Worcestershire sauce. Stir.
Transfer meat mixture to a lg bowl. Then add the cooked rice and 1/4 cup ketchup. Stir.
Mix in 1 cup of the shredded cheese.
Spoon the meat mixture into the bell peppers and fill all of them to the top, if possible.