1. In a large skillet, cook beef over medium heat until brown, stirring to break meat into small pieces. Drain off fat. In a 5- or 6-quart slow cooker, combine cooked beef, salsa, mushrooms, carrots, sweet peppers, tomato paste, basil, oregano, salt, cayenne pepper, and garlic.
2. Cover; cook on low-heat setting for 8 to 10 hours or on high-heat setting for 4 to 5 hours.
3. Reserve and store* 5 cups of the meat mixture; use for Spicy Beef Taco Salad (see recipe below). Serve remaining meat mixture on toasted kaiser rolls. Makes 6 servings.