Heat the vegetable oil in a large skillet over medium heat. Add the sliced sausage and cook until browned, about 5-7 minutes, stirring occasionally.
Add the diced onion, bell pepper, celery, and garlic to the skillet. Sauté for about 3-4 minutes until the vegetables are softened.
Stir in the rice, Cajun seasoning, black pepper, and salt. Cook for about 2 minutes, allowing the rice to toast slightly.
Pour in the chicken or vegetable broth and bring the mixture to a boil. Once boiling, reduce the heat to low and cover the skillet.
Let the rice simmer for approximately 20 minutes, or until the rice is cooked and has absorbed the liquid.
Remove the skillet from heat. Fluff the rice with a fork and garnish with chopped green onions before serving.
For added flavor, consider mixing in cooked shrimp or chicken.
Adjust the seasoning to taste, especially if using different brands of sausages or broth which might vary in saltiness.
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in the microwave or on the stovetop.