In a large stockpot or Dutch oven, cook the bacon on medium high heat until crispy. Removebacon from pan and drain on a paper towel–lined plate. When cool, crumble thebacon.
Reduce heat tomedium and drop the butter into the bacon drippings. Add onion, garlic, celeryand carrots to the pot and cook until tender, about 5 to 6 minutes.
Stir in flour anddry mustard. Cook 1 to 2 minutes. It will become thick.
Slowly add the beer,a little at a time, whisking after each addition until all the beer isincorporated. Then add the chicken bone broth in the same way, whisking aftereach pour. Repeat with the milk. The consistency should be smooth after all theliquid is added.
Add Worcestershiresauce, thyme and salt and bring to a boil. Reduce heat and simmer 5 minutesuntil thick and bubbly.
Reserve ¼ cup ofcheese for topping. Stir the remaining cheese into the soup until melted.
Ladle the soup intobread bowls. Top with reserved cheese, parsley and crumbled cooked bacon. Serve immediately.