Prep the Meat: Place the chuck roast into the bottom of your slow cooker. If the roast is very large, you can cut it into two or three smaller chunks to ensure it fits comfortably and cooks evenly.
Add the Seasoning: Sprinkle the dry onion soup mix evenly over the top of the beef.
Layer the Sauce: Spread the condensed cream of mushroom soup over the roast. Pour the water or beef broth around the sides of the meat (avoiding washing the seasoning off the top).
Slow Cook: Cover and cook on Low for 8 to 10 hours or on High for 5 to 6 hours. The beef is ready when it shreds easily with a fork.
Serve: Remove the meat and shred it slightly before returning it to the slow cooker to toss with the resulting gravy. Serve warm over mashed potatoes, egg noodles, or steamed vegetables.
Tips for Success
Better Searing: For an extra layer of flavor, quickly sear the roast in a hot pan with a tablespoon of oil for 3 minutes per side before adding it to the slow cooker.
Veggie Add-ins: If you want a complete meal in one pot, tuck some baby carrots and quartered potatoes around the roast at the beginning of the cook time.
Creamier Finish: Stir in a dollop of sour cream or a splash of heavy cream right before serving for a velvety sauce texture.