Step one, saute some brats, diced onions, garlic, butter, and about a 1/4 cup of yellow mustard.
Added a cup of heavy cream and some salt and pepper, simmered for about 20 minutes.
While the soup was simmering I caramelized a cup of diced onions, and cooked a brat that was diced. Added a cup of beer and let simmer until the beer had reduced to a glaze. I added a cup of cheddar cheese to the soup and whisked quickly until just combined. After that I poured the brat and onions into the rest of the soup and simmered five more minutes.
It would have been wrong not to serve it in a toasted bread bowl.