Preheat the oven to 180C/350F/Gas 4.
For the chicken, place the meat between two sheets of cling film and flatten out using a meat mallet or rolling pin. Remove the cling film, then season with salt and freshly ground black pepper.
Heat the olive oil in a frying pan and fry the chicken for 1-2 minutes on both sides, or until golden-brown.
For the potato cake, parboil the potato slices in a pan of boiling water for 3-4 minutes, then remove and drain well.
Place the potato slices into a baking tray and lay the chicken on top, skin-side up. Sprinkle over the thyme leaves, garlic and onion and season well with salt and freshly ground black pepper. Drizzle over the olive oil and place into the oven to roast for 4-5 minutes, then pour the wine into the pan and return to the oven to roast for a further 5-6 minutes, or until the chicken is golden-brown and cooked through.
To serve, place the potato cake on a serving plate and place the chicken on top. Drizzle over any pan juices.