Spray 5- to 6-quart slow cooker with cooking spray. In Dutch oven, heat 2 teaspoons oil over medium-high heat. Sprinkle chicken with salt and pepper. Cook chicken in oil until browned on both sides. Remove from Dutch oven; set aside. Discard drippings from Dutch oven; heat 1/2 cup oil over medium-high heat. Gradually stir in flour with whisk; cook 6 to 8 minutes, stirring constantly, until mixture turns chocolate-colored. Reduce heat to medium. Stir in onion mixture and garlic. Cook 3 minutes. Transfer to slow cooker. Stir in broth, okra, sausage, Creole seasoning and bay leaves. Add chicken; stir to combine.