in a Dutch oven or soup pot combine the first 5 ingredients, bring to a boil. reduce heat cover and simmer for 20 minutes or until vegetables are very tender. with potato masher, mash vegetables several times. add bacon, and continue cooking.
meanwhile, melt butter in a small saucepan, stir in the flour and cook, stirring constantly for 1 minute. gradually whisk in milk.
bring to a boil, boil and stir for 2 minutes (mixture will be thick) add to vegetable mixture, stirring constantly.
remove from heat, add cheese and black pepper, stir until cheese is melted (taste for salt and add if needed).