Cut potatoes into 2,5 cm chunks and cook in salted water for 3 to 4 minutes until just starting to soften. Drain and then shake in the pan to roughen the edges.
Mix in the breadcrumbs, paprika and 45 ml oil, so that the potato chunks are well coated.
Heat the remaining oil in a shallow roasting pan, then add the potatoes. Place in a preheated oven at 200 ºC and roast for 20 minutes.
Mix all the ingredients together and set aside in a buttered ovenproof dish. Increase oven temperature to 220 ºC.
Rub the chicken all over with the lemon. Place both lemon halves in the body cavity of the chicken along with the garlic and a few sprigs of fresh thyme.
Brush chicken with melted butter and season with salt and pepper. Place on a rack in a roasting pan. Pour 500 ml water into the roasting pan.
Transfer the potatoes to a lower rack in the oven and place chicken above the potatoes. Roast for 15 minutes, then reduce temperature to 190 ºC.
Place the stuffing alongside the potatoes and roast everything for 1 hour. Test the chicken by pushing a skewer into the thigh. If it is ready, the juices will run clear. If not, cook for another 10 minutes, and test again.