Line a 3-1/2 or 4-quart slow cooker with a plastic slow cooker liner. In a very large bowl, combine sausage, broken tostada shells, sweet pepper, onion, and undrained diced green chiles. In a large bowl, whisk together eggs, soup, and pepper. Pour over sausage mixture; transfer to prepared slow cooker.
Cover and cook on low-heat setting for 5 to 6 hours. Serve mixture garnished with avocados, salsa, and sour cream. Makes 6 servings.