In a soup kettle, saute onion in butter or margarine until tender.
Stir in flour and spices. Gradually add broth, stirring constantly. Bring to a boil; cook and stir for 2 minutes. Add potatoes, and return to a boil. Reduce heat, cover, and simmer for 10 minutes.
Stir in milk and cheese. Heat through. Stir in bacon.