Stir together oil and flour in Dutch oven or heavy-bottomed pot until smooth. Cook over high heat 10 minutes, or until roux turns a dark caramel color, stirring constantly.
2. Add onion, bell pepper, and celery, and cook 5 minutes, or until vegetables are softened. Stir in all remaining ingredients and 4 cups water. Season with salt and pepper. Reduce heat to medium-low, cover, and cook 40 minutes, or until carrots are tender. Serve over rice