Season ribs with salt and pepper, then dredge in flour.
Heat oil in a large pot over medium-high heat. Sear ribs in hot oil in small batches, adding oil as needed, 2 to 3 minutes per batch. Transfer to a plate.
Add onions to the pot and sauté for 2 minutes. Add celery and carrots; sauté for 1 minute. Season with salt and pepper, then stir in garlic, thyme, and bay leaves. Cook until fragrant, about 1 minute.
Pour wine into the pot and bring to a boil while scraping the browned bits of food off the bottom of the pan with a wooden spoon. Add stock and bring to a boil. Reduce the heat to low; add ribs and simmer until meat pulls away easily from the bone and sauce has thickened, about 2 hours.