In a large skillet, heat the olive oil over medium heat. Add the sliced sausage and cook until browned, about 5 minutes.
Add the diced onion and bell pepper to the skillet. Cook for an additional 3-4 minutes until the vegetables are softened.
Stir in the minced garlic and cook for 1 minute until fragrant.
Add the rice, diced tomatoes (with juice), chicken broth, Cajun seasoning, oregano, and black pepper. Stir to combine.
Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for 20 minutes, or until the rice is tender and has absorbed most of the liquid.
Stir in the frozen peas and cook for an additional 5 minutes, uncovered, until heated through.
Remove from heat and let it sit for a few minutes before serving. Garnish with sliced green onions.