Melt the butter in a skillet. Add the onions and garlic. Sauté until the onions are translucent. Add flour to the onions and cook for an additional minute.
Transfer the onion and garlic mixture to a food processor. Add 1 cup of the chicken broth and purée until smooth.
Pour the purée into a Dutch oven. Add the rest of the chicken broth and the lager. Bring to a boil. Reduce heat and simmer for 15 minutes.
Remove from heat and add the cream cheese and shredded cheese. Whisk until melted.
Add the mustard powder, Worcestershire sauce and hot sauce. Stir to incorporate. Add salt and pepper to taste.
Ladle the soup into bowls and garnish with bacon bits and scallions.
Notes
TIP: This makes an excellent cheese dip for pretzels, also!