Bring first 6 ingredients to a boil in a Dutch oven. Cover, reduce heat, and simmer 15-20 minutes or until vegetables are tender. Remove from heat and stir in corn.
Melt butter in a heavy saucepan over low heat; add flour, whisking until smooth. Cook 1 minute, whisking constantly. Gradually add in milk, cooking over medium heat and whisking until the mixture becomes thickened and bubbly. Add cheese stiring until blended.
Stir cheese mixture into vegetable mixture. Cook over medium heat, stirring constantly, until thoroughly heated.