Preheat oven to 350 degrees. Heat oil in large pot over high heat. Sprinkle ribs with salt and pepper. Working in batches, brown ribs on all sides. Return all ribs to pot. Add carrots, onion, celery and garlic; cook 5 minutes, stirring occasionally. Add honey; cook 2 minutes. Add vinegar; boil until most liquid is absorbed, about 8 minutes. Add broth, red wine, port, thyme and bay leaf; boil 5 minutes. Cover; transfer to oven. Bake until meat is falling off bones, about 2 hours. Remove ribs from pan and put pan liquid in saucepot; boil until slightly reduced. Add salt and pepper. Mix butter and flour in small bowl, then whisk into sauce. Boil until thick, about 3 minutes. Add ribs and serve.