Add butter/oil to the pan and cook over medium heat. When the pan is hot add onion, pepper, and garlic. Cook for 5 minutes. Add sausage and cook an additional 3 minutes.
In a separate bowl add diced tomatoes and cajun seasoning, and stir. Add cooked rice and stir well.
Add rice mixture to a pan with vegetables and sausage. Stir well, cover, and cook over low heat for 5 minutes (or until heated).
Dish onto plates and sprinkle with fresh parsley and hot sauce.