Prep the Beef: If desired, brown the beef chunks in a skillet with olive oil over medium-high heat for about 3 minutes per side. This step is optional but adds extra flavor.
Assemble in Slow Cooker: Add the beef chunks to the slow cooker. Sprinkle with garlic, Italian seasoning, onion powder, paprika, salt, and pepper. Stir to coat the beef evenly.
Add Broth and Tomato Paste: Pour in the beef broth and stir in the tomato paste. This creates the flavorful base for the sauce.
Cook: Cover the slow cooker and cook on low for 6-8 hours or high for 3-4 hours, until the beef is tender and easily shredded with a fork.
Cook the Pasta: About 20 minutes before the beef is done, cook the pasta in a large pot of salted boiling water according to package instructions. Drain and set aside.
Combine Pasta and Beef: Once the beef is tender, shred it with a fork directly in the slow cooker or leave the chunks whole. Add the cooked pasta to the slow cooker and stir to combine.
Add Cheese: Stir in the Parmesan or mozzarella cheese until melted and creamy.
Serve: Garnish with fresh parsley if desired, and serve warm.