Prepare the beef: If using a whole chuck roast, cut the beef into 2-inch cubes. Pat the beef dry with paper towels, then season with salt and pepper.
Mix the sauce: In a bowl, combine the cream of mushroom soup, dry onion soup mix, beef broth, and soy sauce. Stir until the mixture is well combined.
Layer the ingredients: Place the beef into the slow cooker. Pour the soup mixture over the beef, making sure all the pieces are evenly coated.
Slow cook: Cover the slow cooker with a lid and cook on low for 6-8 hours, or until the beef is fork-tender and the sauce has thickened. Avoid opening the lid during cooking to maintain the heat.
Finishing touches: Once cooked, taste the gravy and adjust seasoning with more salt or pepper if necessary. If desired, stir in the sour cream for a richer, creamier sauce.
Serve: Serve the beef tips over mashed potatoes, rice, or your favorite side. Spoon the delicious gravy over the beef for extra flavor.