Preheat your oven to 375°F (190°C).
In a skillet, heat olive oil over medium heat. Add chopped onion and garlic, sauté until translucent.
Add chorizo to the skillet, breaking it apart with a spatula. Cook until browned and cooked through.
Stir in diced tomatoes, smoked paprika, cumin, salt, and pepper. Let simmer for 5 minutes.
Remove from heat and mix in cooked rice and half of the shredded cheese.
Stuff each bell pepper generously with the chorizo and rice mixture.
Place the stuffed peppers upright in a baking dish. Sprinkle remaining cheese on top.
Cover with foil and bake for 30 minutes. Remove foil and bake an additional 5 minutes until cheese is bubbly and slightly browned.
Garnish with fresh cilantro or parsley if desired. Serve warm and enjoy!