01 - Set oven temperature to 375°F (190°C).
02 - Cut off tops, remove seeds and membranes, then position peppers upright in a baking dish.
03 - Heat olive oil in a large skillet over medium heat. Add chopped onion and cook for approximately 4 minutes until softened.
04 - Add minced garlic, cook for 1 minute, then incorporate ground beef. Break meat apart and brown thoroughly over 6 to 7 minutes.
05 - Mix in cherry tomatoes, canned diced tomatoes, cumin, smoked paprika, oregano, salt, and black pepper. Simmer for 5 minutes until most moisture evaporates.
06 - Remove skillet from heat. Fold in cooked rice, crumbled feta, chopped parsley, and optional pine nuts.
07 - Spoon the mixture evenly into each prepared bell pepper, pressing gently to pack the filling.
08 - Return pepper tops if desired. Pour 2 to 3 tablespoons of water into the baking dish’s bottom.
09 - Cover the dish with foil and bake for 30 minutes in preheated oven.
10 - Remove foil and bake an additional 15 minutes until peppers are tender and tops develop a light brown color.
11 - Allow peppers to cool for 5 minutes before serving. Garnish with extra parsley as desired.