In a medium-large, deep skillet, cook bacon over medium heat until crispy. Remove bacon to a paper towel-lined plate and remove all but 1-2 tablespoons of the grease from the pan.
Reduce heat slightly (just shy of medium) and add onions to the bacon grease. Cook for one minute and then add broccoli. Continue to cook until broccoli is beginning to be tender, stirring frequently. Add garlic and cook and stir for one minute until fragrant. Add flour and stir to combine, continuing to stir and cook for 1-2 minutes.
Add in beer while stirring and scraping the bottom of the pan. Increase heat to high and bring beer to a boil. Cook at a boil for 2-3 minutes or until beer is reduced by about half.
Reduce heat to low and stir in cheeses. Stir until melted. Add cooked bacon.
Taste and add pepper as desired.
Best served warm with soft bread, crostini (see below) or pretzels.
For crostini:
Preheat broiler.
Arrange slices of bread in a single layer on a sheet pan. Sprinkle or brush bread with olive oil. Broil on one side for 2-5 minutes or until golden brown.