Cook the bacon: Cut the bacon into small pieces and add it to a large soup pot. Cook over medium heat for about 10 minutes, stirring occasionally, until crisp. Transfer the bacon to a paper towel-lined plate, leaving the bacon drippings in the pot.
Sauté the vegetables: Add the chopped onion and celery to the bacon drippings. Cook for 5–7 minutes, stirring occasionally, until softened and lightly browned.
Make the roux: Add the butter and minced garlic. Once the butter has melted, sprinkle in the flour and stir well. Cook for 1–2 minutes, stirring constantly.
Add the broth: Slowly whisk in the chicken broth, making sure the flour is fully incorporated and there are no lumps.
Add the beer and seasonings: Stir in the beer, heavy cream, Worcestershire sauce, Dijon mustard, cayenne pepper, and half of the cooked bacon.
Simmer: Bring the soup to a gentle boil, then reduce the heat and simmer uncovered for 15–20 minutes, stirring occasionally, until the soup has thickened and reduced slightly.
Add the cheese: Remove the pot from the heat. Gradually stir in the shredded cheddar, a little at a time, until completely melted and smooth. Taste and season with salt and pepper if needed.
Serve: Ladle the soup into bowls and top with the remaining crispy bacon and chopped scallions. Serve warm with your favorite bread, biscuits, or sourdough for dipping.
