Add beef, broth, and chopped onions to slow cooker. Sprinkle with salt, pepper, and Italian seasoning.
Cover and cook on low for 8 hours or on high for 4 hours.
About 10-15 minutes before serving, Transfer slow cooker contents to a large stock pot and bring to a boil. Whisk together cold water and corn starch, add to pot, and stir until thickened. Serve over rice and sprinkle with chopped parsley if desired. Enjoy!
Notes
Beef: this is a great chance to use inexpensive cuts like stew meat - the slow cooker will tenderize the beef and it will absorb lots of delicious flavor.