Heat olive oil in a large skillet over medium heat.
Add the sliced smoked sausage and cook until browned, about 3 minutes per side.
Add the diced bell pepper, onion, and garlic to the skillet. Cook until the vegetables are soft, about 3-5 minutes.
Stir in the rice, paprika, salt, black pepper, oregano, and red pepper flakes.
Pour in the chicken broth and diced tomatoes with their juices. Stir well to combine.
Bring the mixture to a boil, then reduce heat to low. Cover and let it simmer for 15-20 minutes, or until the rice is tender and the liquid is absorbed.
Remove from heat and let sit for 5 minutes before fluffing with a fork.
If using, sprinkle with shredded cheddar cheese and fresh parsley before serving.