2) Season the chicken breasts with salt and pepper and dust with flour, shaking off any excess.
3) Add 2 tbsp of oil to the pan. Place the chicken in the pan smooth-side down and cook until golden, about 5 minutes per side. Transfer to a baking dish and bake until cooked through, about 8 minutes.
4) Meanwhile, add the onion and apple to the pan, along with a little oil if the pan is dry, and increase the heat to high. Cook, turning the onions and apples in the pan, until the onion has softened slightly and the apple is golden brown, about 2 minutes.
5) Remove the chicken from the oven and add any juices to the sauce. Divide the chicken between 4 plates and spoon the apple, onion and pan sauce over each plate. Sprinkle with the parsley and serve.