Season the rabbit with salt and pepper to taste. Place the flour in a bowl and dredge the pieces of rabbit in the flour. Pat off the excess flour, leaving a thin coating of flour on the meat. Heat a large frying pan and melt the butter. Lightly brown the rabbit on both sides and remove the meat to a 6-quart casserole. Deglaze the pan with 1/4 cup of the chicken stock and add to the casserole.
Heat the frying pan again and brown the pancetta until clear. Add the pancetta to the casserole. Heat the pan again and add the oil, garlic, and onion. Sauté until the onion is tender. Add the mushrooms, sauté 2 minutes, and add the remaining ingredients, including the remaining chicken stock. Stir together until the tomato paste dissolves. Pour over everything in the casserole.
Bring to a simmer and cover. Simmer gently 35 minutes, turning the meat a couple of times. Turn off the heat and leave covered for ten minutes to allow the meat to relax. Add salt and pepper to taste if needed.
Servings: 4 to 6