Slice the onion.

Place the sliced onion in the bottom of a roasting pan.

Place the beef chuck roast on top of the onions.

In a separate bowl, combine the beef broth, flour, chopped parsley, and onion soup mix.

Pour the mixture over the beef roast.

Cover the roasting pan tightly with a lid or aluminum foil.

Ensure a tight seal to trap moisture during cooking.

Bake at 350 degrees Fahrenheit (175 degrees Celsius) for 3-4 hours.

Check for tenderness; the roast should be easily pierced with a fork.

Remove the roast from the pan.

Stir the gravy in the pan to thicken.

Slice the roast and serve with the gravy.