Preheat oven to 180C/160C if fan forced.

Heat oil in a large heavy based casserole dish over medium high heat.

Add chicken in batches and cook for 5-6 minutes, or until golden brown. Transfer to a bowl.

Add onion, carrot, celery, and bacon to the casserole dish. Cook, stirring, for 5 minutes, or until the onion has softened.

Add garlic and sage. Cook for 1 minute, or until fragrant.

Add wine and bring to a boil.

Stir in the flour and cook for 1 minute.

Slowly add the stock, stirring constantly to avoid lumps.

Return the chicken to the casserole dish.

Cover the dish, bring to a boil, and then transfer to the preheated oven.

Bake for 1 hour, then remove the lid and bake uncovered for another hour, or until the chicken is tender.

Let cool slightly before serving.