Coat a large Dutch oven with cooking spray; place over medium-high heat until hot. Add onion and next 5 ingredients; sauté 4 minutes or until tender, adding water, 1 tablespoon at a time, to prevent scorching, if necessary. Stir in half-and-half and next 5 ingredients. Bring to a boil; reduce heat, and simmer, uncovered, 8 minutes or until thoroughly heated. Ladle soup into bowls; top with sour cream.