Cover partially, and cook for about 30 minutes, allowing the ingredients to combine into the best flavour. In fact, if you start this early enough, let it simmer on low for a good 45 min to an hour. Season with salt and pepper. Start with the pepper, and taste. Then adjust the salt, but do not let it become the dominant flavour.
Set 6 ovenproof bowls onto a rimmed baking sheet. Don't use too large of bowl, or the bread will end up falling in, and the cheese won't make a fabulous crust.
Place one or two slices of the bread on top of each soup bowl. You ideally want most of the soup covered. Cover each bowl with 2/3 cup of cheese (or more!!)
Place the baking sheet in the upper third of the oven under the broiler. Broil until the cheese is melted, bubbling and crusting up all over. Just make sure the bread doesn't burn.
Like I mentioned above, the more cheese the better. So feel free to grate or shave much more than I state. I'm being conservative, and erring on the side of health (if you consider this soup HEALTHY!)
Test the broth to ensure that it isn't too salty. The Maggi or Worcestershire sauce contain salt, so really, you won't need a lot extra. I use either of these, as they truly bring out the savouriness of the beef broth. You can omit this, but then you will be adding more salt. Play it by ear. Or tongue, more correctly.
To make it even more special, why not make a great bone broth? See my recipe here. It can be made with a great combo of bones including shanks, marrow, turkey and chicken all in one pot. It makes for a really well rounded broth.
To make this soup without feeling chained to the stove, why not caramelize your onions in advance? You can store them in the fridge till you are ready to make the soup. I have been even known to make the soup in advance and store this in the fridge till the next evening when I am having company. All you need to do is reheat the soup and top with the bread and cheese! Voila- one less thing to worry on game day!