Sauté the Sausage & Veggies:
Heat olive oil in a large skillet over medium heat. Add the sliced sausage and cook until browned, about 3-4 minutes per side. Remove from the pan and set aside.
In the same skillet, add the diced onion and bell pepper. Sauté for 2-3 minutes until softened. Add the garlic and cook for another 30 seconds.
Cook the Rice:
Stir in the uncooked rice, chicken broth, diced tomatoes, paprika, oregano, salt, black pepper, and red pepper flakes (if using).
Bring the mixture to a simmer, then reduce the heat to low. Cover and cook for 15-20 minutes, stirring occasionally, until the rice is tender and most of the liquid is absorbed.
Combine & Serve:
Return the cooked sausage to the skillet and stir to combine. If using cheese, sprinkle it over the top and let it melt.
Garnish with sliced green onions and serve hot.