whisk 1 tablespoon cornstarch with 2 tablespoons cold water, stir it into the hot sauce in the slow cooker about 20 minutes before serving, and let it cook on HIGH until the gravy lightly thickens.
Finally, if sodium is a concern, choose low-sodium broth and a reduced-sodium condensed soup, and taste before adding any extra salt—onion soup mix is flavorful and can be quite salty on its own.
