In a 4 to 5 quart Dutch oven, cook bacon over medium heat until crispy. Remove bacon from pan, drain on paper towels, set aside. Drain off bacon fat, leaving 1 tablespoon fat in pan.
Add onion, garlic, celery, green pepper, fresh mushrooms, carrots and oil. Saute until vegetables are soften, about 10 minutes.
Add flour, and stir constantly for about 4 minutes.
Whisk in chicken stock, half & half and beer. Bring to a boil, boil for 1 minute.
Reduce heat to a simmer and cook for 10 minutes, stirring constantly.
Stir in cheese, Tabasco sauce, Worcestershire sauce, salt and pepper, until cheese is melted and soup is smooth. If soup is to thick, stir in a small amount of warm milk.
Garnish with chopped chives and crumbled bacon.