Heat the oven to 200°C/ fan180°C/gas 6. Chop the potatoes into chunks. Slice the garlic bulb horizontally. Slice the lemon and toss with the potatoes, oregano and thyme, garlic, olives and wine in a roasting tin large enough to fit everything in.
Heat a pan over a medium heat. Rub the chicken thighs with olive oil, season and fry, skin-side down, for 8-10 minutes until golden. Quickly brown on the other side, then transfer to the roasting tin. Drizzle with more olive oil.
Roast for 30-40 minutes or until the thighs are cooked (the juices will run clear when the thickest part of each thigh is pierced with a skewer). Remove from the oven and rest for 5 minutes, covered with foil. Chop the parsley, then toss through to serve.