Preheat the oven. Set to 375°F (190°C). Lightly oil a 9x13-inch baking dish.
Prep the peppers. Slice off the tops (keep them as “lids”), remove seeds and membranes, and rinse.
If you want spooky faces, use a small sharp paring knife to carve triangle eyes and a toothy grin. Go slowly—small cuts first, then widen.
Par-cook the peppers (optional, but recommended for softer peppers). Place them open-side down in the baking dish, add 1/4 cup water to the pan, cover with foil, and bake 10 minutes. Drain any water, then set peppers aside.
Cook the aromatics and meat. Warm olive oil in a large skillet over medium heat.
Add onion and cook 4–5 minutes until translucent. Stir in garlic for 30 seconds. Add the ground meat and cook, breaking it up, until browned.
Season with salt and pepper.
Build the filling. Stir in diced tomatoes, tomato sauce, broth, Worcestershire (if using), Italian seasoning, smoked paprika, and red pepper flakes. Simmer 5–7 minutes until slightly thickened.
Add rice and cheese. Fold in the cooked rice and 1 cup shredded cheese. Taste and adjust seasoning.
The mixture should be saucy but not soupy.
Stuff the peppers. Stand peppers upright in the baking dish. Spoon the filling into each, mounding slightly. Sprinkle remaining 1/2 cup cheese on top and place the pepper “lids” back on or leave them off for a melty top.
Bake. Cover loosely with foil and bake 20 minutes.
Remove foil and bake another 10–15 minutes, until peppers are tender and cheese is bubbly.
Garnish and serve. Let rest 5 minutes. Sprinkle with chopped parsley or cilantro. Serve warm.