Combine first 7 ingredients in a large soup pot; bring to a boil over medium heat. Reduce heat; cover and simmer until vegetables are tender. Stir in ham; set aside. In a separate saucepan, melt margarine; stir in flour until smooth. Gradually add milk; bring to a boil. Cook and stir for 2 minutes, until thickened. Stir in cheese until melted; add to vegetable mixture and heat through.