Season the meat with salt. Optional: Marinate overnight in red wine, thyme, salt, pepper and oil.
In a sauté pan, heat some oil and brown the chicken pieces for about 2 minutes on each side.
Set aside.
In a pot, on medium heat, cook the onion, pepper and celery in the butter for 10 minutes.
Once they’re soft, add all the other ingredients and the chicken. Simmer for 30 minutes, stirring occasionally. Season the casserole with salt and be generous with the black pepper.