Coat a large Dutch oven with cooking spray; add oil, and place over medium-high heat until hot. Add carrot, 1 cup onion, green pepper, and garlic; saute until tender. Add potato and next 8 ingredients; bring to a boil. Reduce heat; simmer, uncovered, 30 minutes. Cover and simmer an additional 30 minutes or until potato is tender. Add beans, and cook, uncovered, an additional 5 minutes.
Spoon chili into individual serving bowls; sprinkle each serving with 1 tablespoon cheese. If desired, top with sour cream and green onions.