Spray the crockpot vessel with non-stick cooking spray.
Place the sliced onions in the bottom of your slow cooker.
Layer the cube steaks over the onions. Sprinkle with the brown gravy mix.
In a mixing bowl, combine the golden mushroom soup, beef broth, and Worcestershire sauce. Stir until well combined.
Pour the soup mixture over the cube steaks in the slow cooker, ensuring they are well-covered.
Cover the slow cooker with its lid and cook on low heat for 6-8 hours or on high heat for 3-4 hours. Cooking times may vary depending on your slow cooker.
Notes
I thought the gravy was just right. However, if you prefer a thicker gravy, about 30 minutes before serving, you can mix 2 tablespoons of all-purpose flour with ¼ cup of cold water until smooth. Stir the flour mixture into the slow cooker, cover, and continue cooking until the gravy thickens slightly.