Start by preheating your oven to 375°F. While it heats, cook your basmati rice according to package directions — usually about 15 minutes. Once it's done, set it aside and let it cool for a few minutes so it's easier to handle. Don't panic if a few grains stick together; that's totally normal.
Slice the tops off your 4 large bell peppers and scoop out the seeds and white ribs inside. I run mine under cold water to rinse them out completely. Stand them upright in a baking dish and set aside — they're ready for filling.
Heat 2 tbsp olive oil in a large skillet over medium-high heat. Add your 1/2 cup chopped onion and cook for about 2 minutes until it gets soft. Then add your 2 minced garlic cloves and stir constantly for 30 seconds so it doesn't burn. The kitchen smells amazing at this point.
Add your 1 lb ground beef to the skillet and break it apart with a wooden spoon. Cook it for 5-6 minutes until it's completely browned and no pink remains. Drain off any excess fat if there's a lot pooling at the bottom. I usually tilt the pan and use a spoon to soak it up with paper towels.
Stir in 1 tsp ground cumin, 1/2 tsp smoked paprika, 1/4 tsp black pepper, and 1/4 tsp salt into the meat mixture. Mix well so the spices coat everything evenly. Then add your cooked rice, 1 cup diced tomatoes, and 1/2 cup shredded cheese. Fold everything together gently until it's combined — you're looking for a stuffed pepper recipe filling that holds together but isn't packed too tight.
Spoon your filling mixture into each pepper, packing it down gently so it fills to the top. You'll have plenty to mound slightly above the rim. Pour 1 cup chicken broth into the bottom of the baking dish (not over the peppers). This keeps them from drying out and adds flavor as they bake.
Cover the baking dish tightly with foil and bake for 30 minutes. Then remove the foil and bake uncovered for another 15 minutes so the tops get a little color and the peppers are tender but still hold their shape. Let them sit for 5 minutes before serving — they're hot and need that time to set slightly.