This dish is made from a recipe in The Country Cooking of France by Anne Willan.
3 cups red wine
1 tsp. whole black peppercorns
3 cloves garlic (1 whole, 2 chopped)
2 ribs celery, thinly sliced
1 medium carrot, thinly sliced
1 medium yellow onion, thinly sliced
1 (5-6-lb.) chicken, cut into 10 pieces
3 tbsp. olive oil
8 sprigs flat-leaf parsley plus 1 tbsp. chopped leaves
2 bay leaves
2 sprigs thyme
1⁄2 lb. slab bacon, cut into 2″-long slivers
3 tbsp. flour
2 cups Chicken Stock
2 shallots, chopped
Kosher salt and freshly ground black pepper
4 tbsp. butter
18 pearl onions, peeled (see Pearls of Wisdom)
1⁄2 lb. button mushrooms, quartered
Bring wine, peppercorns, whole garlic, celery, carrots, and yellow onions to a boil in a pot; reduce heat; simmer for 5 minutes. Let cool, pour over chicken in a bowl, and drizzle with 1 tbsp. oil. Cover and marinate overnight.
Heat oven to 325°. Tie parsley sprigs, bay leaves, and thyme together; set aside. Remove chicken from marinade; pat dry. Strain marinade; reserve liquid and solids separately. Heat 1 tbsp. oil in a wide pot over medium heat. Add bacon; cook until crisp, 6–8 minutes. Using a slotted spoon, transfer bacon to a bowl; increase heat to medium-high. Working in 2 batches, brown chicken, 6–8 minutes; transfer to a plate. Add reserved solids; cook until soft, 10–12 minutes. Sprinkle in flour; cook, stirring, for 1 minute. Whisk in reserved liquid; boil. Simmer for 1 minute. Stir in remaining garlic, stock, shallots, and salt and pepper to taste; nestle chicken and herb bundle in vegetables. Bake, covered, until tender, about 1 1⁄4 hours. Transfer chicken to a plate; cover with foil. Strain sauce; keep warm.
While chicken is cooking, heat 1 tbsp. butter and remaining oil in a skillet over medium heat. Add pearl onions; cook until golden, 4–5 minutes. Reduce heat to medium-low; cook, covered, until tender, 8–10 minutes. Combine onions with bacon. Heat remaining butter over medium-high heat; cook mushrooms until tender, 4–5 minutes. Arrange chicken on platter; top with sauce, bacon, onions, mushrooms, and remaining parsley.