Leave only 2 Tbsp. fat in the pot and to it add the 2 Tbsp. butter. Melt over medium heat. Add onions, red pepper, carrots. Cover and cook for 15 minutes. Add the garlic and cook for 1 additional minute. Add the flour and cook stirring constantly for 3 minutes making sure not to brown. Add the pale ale and cook for 5 minutes, stirring constantly. Add the dry mustard, Worcestershire, cayenne, milk and broth. Whisk together and bring to a simmer and then reduce the heat to medium-low and continue cooking for 15 minutes.