Cook and crumble Italian sausage in a skillet until done. Combine the cooked sausage with spaghetti sauce and tomatoes in a crockpot. Cover with a lid and cook on low for 6-8 hours.
Add tortellini to the mixture and sprinkle both cheeses on top. Cover the slow cooker with the lid again and let it cook for an additional 15 minutes. Serve and enjoy!