To a large pan over medium heat, add the sausage, bell peppers, and carrots. Break the sausage up and cook it through. Remove any excess grease from the pan.
Add the diced tomatoes, tomato sauce, cheese, and salt and pepper and stir. Let simmer for five minutes, stirring occasionally.
Grease a 9x13 baking dish with nonstick spray. Place the casserole mixture in the baking dish and spread it out. Open the biscuits and peel each biscuit into two to create twice as many biscuits. This will make them quite a bit thinner. Place the biscuits on top of the casserole next to each other. Drizzle the butter over the top then sprinkle the garlic salt and oregano on top as well.