Heat a large stock pot over medium heat and add chopped bacon. Fry until crispy and fat is rendered, them remove bacon with a slotted spoon and place on a paper towel to drain. Reduce heat to low and add onions, peppers and garlic, stirring to coat. Cook for about 10 minutes, until vegetables are translucent, stirring occasionally. Increase heat to medium-high and add in butter. Once sizzling, which in flour and cook for 3-4 minutes until flour is nutty and golden. Add in beer and stirring constantly, cook for 5 minutes so they alcohol cooks out and the mixture somewhat thickens.