"Go ahead and print this recipe for your friends! They WILL ask for it. This pot roast has just a hint of cayenne pepper which really enhances the flavor without overpowering or making it "spicy". Oh, and did I mention it cooks itself and makes its own gravy?"
Turn on slow cooker and set to "low". Combine soup, broth, gravy mix, water, and spices in slow cooker and whisk until smooth.
Add chuck roast and top with onion. Place lid on cooker and leave it alone. No peeking!
After about 6 hours, you can add carrots and potatoes (if using). Just tuck them in around the sides. It's okay if they're not all down in the broth. They'll still absorb some of those great flavors. Replace cover and continue to cook on "low" 2 more hours until roast is done, a total of about 8-10 hours, or when roast pulls apart with fork.