Place the chopped bacon in a large heavy pot or Dutch oven and cook over medium heat until it turns lightly browned and releases fat, about 5 minutes. Drain some fat if the pot is very greasy, leaving enough to sauté the vegetables.

Add the finely chopped onion, celery, minced garlic, and butter to the pot. Sauté over medium heat until the onion becomes soft and translucent, about 5 minutes.

Sprinkle in the flour and stir constantly, cooking until the mixture turns a light golden color and develops a toasty aroma, roughly 4 minutes.

Gradually whisk in the chicken stock and bring the mixture to a boil. Let it boil for about 1 minute, then lower the heat to a simmer and cook uncovered for 15 minutes, stirring occasionally.

Stir in the milk and continue to simmer gently for another 15 minutes. Avoid bringing the soup to a boil once the milk has been added to prevent scorching.

Remove the pot from the heat and fold in the grated cheddar until it melts. Add the Tabasco, Worcestershire sauce, and season with kosher salt and freshly ground black pepper to taste.

Use an immersion blender to purée the soup until it is mostly smooth with some texture remaining. Alternatively, carefully transfer portions to a blender and return to the pot.

Stir in the beer, taste and adjust seasoning as needed. Serve hot, garnished with chopped green onion or chives if desired.