Pre-heat the oven to 325°F.
Pre-heat a large Dutch oven over medium-high heat.
Add the oil, pancetta and the guanciale or bacon and lightly brown. Add the chicken wings; brown on each side and remove everything from the pan. Add the celery, onions, garlic, anchovies, rosemary, thyme and bay leaves to the drippings and cook to tender. Stir in the tomato paste; cook for 1 minute, then add the Worcestershire, soy and wine and stir until almost evaporated. Add the butter and melt, then add the flour and stir for 1 minute. Add the stock, wings and bacon back to pot with the potatoes and the chicken thighs. Bring the stew to a simmer, then transfer to the oven and roast for about 45-50 minutes, until the potatoes are tender and the chicken is cooked through.
To serve, remove and discard the bay leaves and chicken wings and stir in the lemon juice and parsley.