These stuffed chicken breasts look fancy but are actually incredibly each to make. The chicken breasts are filled with a chestnut, mushroom, garlic, onion stuffing, wrapped in bacon and then baked until the bacon is crisp and the chicken is moist and tender. This is a great dish to serve when you want to impress.
Preheat the oven to 375º Fahrenheit (190º Celsius) and place a baking dish or cast iron skillet large enough to fit 4 chicken breasts in the oven to heat up
Heat the olive oil in a large skillet on medium high heat. Add in the garlic, onion and mushroom, season with salt, pepper and sage and saute for 8 minutes until the onion begins to soften. Next add in the chopped chestnuts and chicken stock and leave the mixture to cook for approx 6-8 minutes until all of the liquid has evaporated.
While the filling is cooking, prepare the chicken breasts. Place a chicken breast on a cutting board and, holding your knife parallel to the cutting board, cut horizontally three fourths of the way through the thickest part of the breast so that the breast can be opened flat onto the cutting board like a book. Repeat with the remaining chicken breasts.
Lay all of the chicken breasts open on a cutting board and season with salt and pepper. Place 2-3 spoonfuls of the mushroom and chestnut filling on one half of an opened chicken breast and then close the chicken breast by folding the top half of the breast over the filling. Repeat with the remaining breasts.
Using 2-3 strips of bacon per breast, wrap them around each chicken breast which will help to keep all of the stuffing inside the breast. Place the chicken breasts with the bacon "seam" side down in the baking dish/cast iron skillet that was heating in the oven (this will help the bacon on the under side of the chicken cook properly).
Bake the chicken in the oven for 25-30 minutes until the bacon is crisp and the chicken reaches an internal temperature of 165ºF. When the chicken is done cooking, remove it from the oven and pour all of the liquid from the bottom of the pan into a small sauce pan. Cover the chicken breasts with aluminum foil to keep warm while you prepare the sauce.
To the saucepan with the drippings add in the chicken stock and white wine vinegar and bring to a gentle simmer on medium high heat. In a bowl whisk together the arrowroot (if using) with 2 tbsp of water. Once the arrowroot has completely dissolved, pour it into the sauce. Leave the sauce to simmer for approximately 10 minutes until it has reduced by half.
Cut the chicken breasts into approximately 4 slices and serve them with the sauce poured over top and an optional sprinkle of parsley for garnish.