Preheat oven to 325.

In a large Dutch oven, cook bacon over medium-high heat until crisp and golden brown, about 8 minutes. Using a slotted spoon, transfer bacon to a paper-towel-lined plate and set aside.

Season chicken with 1 tablespoon salt and 2 teaspoons white pepper. In the same Dutch oven, working in batches, brown chicken in rendered bacon fat over medium-high heat until golden on all sides, 3 to 4 minutes per side. Once browned, transfer chicken to a platter and set aside. Repeat with remaining chicken.

Pour off and discard any remaining fat and any dark bits left in pan, and return pan to stove. Add butter and whisk in flour, stirring constantly and reaching every portion of the bottom of the pot, until the roux begins to take on some color. Reduce heat to medium or medium-low and continue cooking and stirring constantly until the roux reaches a dark blond color. Add fennel, leeks, mushrooms, parsnip, celery, and garlic and cook until vegetables are tender, 6 to 8 minutes. Add 1 cup wine and cook, stirring, until almost evaporated.

Add grapes, stock, thyme, bay leaf, remaining wine, 1 teaspoon salt, and 1/2 teaspoon white pepper and bring to a brisk simmer. Add browned chicken back to pan; cover and place in oven. Cook until chicken is tender and sauce has thickened, 2 to 2 1/2 hours.

Remove thyme sprigs and bay leaf; discard. Serve directly from the Dutch oven, over cooked noodles or rice, or with warm French bread. Garnish with bacon.