Season the chicken with salt and pepper.
In a large skillet, heat oil over medium high heat.
Cook the chicken, skin side down, until the skin turns golden brown (about 4 minutes).
Combine the onion, garlic, thyme and rosemary in a 5 to 6-quart slow cooker and season with salt and pepper.
Top with the chicken, skin side up.
Scrape any juices from the pan on top of the chicken.
In a small bowl, whisk together the wine, broth and flour until smooth and pour it over the chicken in the slow cooker.
Cover and cook until the chicken is tender, about 3½ hours on HIGH or 7 hours on LOW.
Serve the chicken topped with sauce. Serve over rice, couscous, polenta or potatoes.
