Preheat the oven to 400°F and place the oven rack in the top third position. Prepare a sheet pan or 13x9 baking dish with parchment paper or foil.
To prepare the peppers, stand each one up and use a small knife to cut around the stem at the shoulders of each pepper. Remove the stem portion and cut the remaining pepper around it to be added to the filling. Cut each pepper in half vertically and remove the white ribs and excess seeds.
Place the pepper halves on the prepared pan and drizzle with oil on all sides and lightly season with salt. Roast for 20 minutes, flipping the peppers halfway through. The peppers should look a little more translucent, with softened and slightly darkened edges and smell fragrant.
While your peppers are roasting, prepare the filling by heating the oil in a large nonstick skillet over medium heat. Add the onion and bell pepper and cook until translucent and softened, about 5 minutes. Add the minced garlic and cook for an additional minute.
Add in the ground beef, salt, and pepper. Brown the meat, breaking it up as it cooks, about 8 minutes. Stir in the chili powder, paprika, cumin, coriander, garlic powder, onion powder, and cook for an additional minute, until toasted and fragrant.
Stir in the Worcestershire sauce, cooked rice, and tomato sauce and cook for 2 minutes until warmed through. Remove from heat and stir in 1 ¼ cup of shredded cheese and parsley.
When ready, remove the peppers from the oven and portion the filling into each half. Smooth the tops of the filling and garnish with the remaining shredded cheese.
Place back in the oven and cook for 15-18 minutes, until peppers are a bit softer and the cheese is bubbling. Remove from the oven, let sit for 5 minutes, then serve and enjoy!