Put the bacon into a large heavy pot and place it over medium heat, cook until it gives up its fat, 4 mins. Stir in the onions and cook, ,stirring until they start to turn translucent, 4 mins. Stir in the garlic and cook until you can smell it, about 1 min. Add the broth, tomatoes, ketchup Worcestershire and chili powder. Stir in the black beans, bring to a boil Boil gently 10 mins. Bake for 1 hour at 200 degrees if you wish to thicken