In a Dutch oven, saute red peppers, carrots, onions, celery and garlic in oil until tender. , Stir in the broth, rice, thyme, salt, pepper and cayenne; bring to a boil. Reduce heat; cover and simmer for 20-25 minutes or until the vegetables and rice are tender. , Cool for 30 minutes. Puree in small batches in a blender; return to pan. Add red pepper flakes; heat through.