Place large flameproof casserole or other heavy-bottomed pan over medium heat. Add bacon, and cook until most of the fat has been rendered. Add onions and sauté until softened, about 10 minutes. Using a slotted spoon, transfer mixture to plate, leaving behind as much liquid fat as possible.

Place pan over medium-high heat. Working in batches (do not overcrowd pan), brown chicken pieces on both sides, transferring them to a plate after they are browned.

Reduce heat to medium-low. Add mushrooms, garlic, 3 tablespoons of parsley and 2 tablespoons of tarragon. Sauté until mushrooms are coated in fat, about 1 minute. Return chicken pieces, onions and bacon to pan. Add wine, and raise heat to bring to a boil. Partially cover, turn heat to low, and simmer for 1 hour.

To serve immediately, sprinkle with remaining parsley and tarragon. For best results, cool, and refrigerate overnight. The next day remove any chilled fat on surface with paper towels. Reheat gently, sprinkle with parsley and tarragon, and serve.