Preheat the oven to 200C/400F/Gas 6.
For the chicken, season the chicken with salt and freshly ground black pepper and place the halved lemon, garlic and lemon thyme inside the chicken. (If using two chickens divide these ingredients between the two.) Place the chicken onto a roasting tray, smearing the skin with butter. Place in the oven and cook for 1-2 hours, basting occasionally until completely cooked and the juices run clear when a skewer is inserted into the thickest part.
Ten minutes before removing the chicken from the oven, pour the water into the roasting tray. When the chicken is cooked, remove from the oven and squeeze the fresh lemon juice over the chicken. Leave to rest for 15 minutes before straining the juices into a pan to keep warm.
For the chicory salad, place the garlic, white wine vinegar and Dijon mustard into a bowl. Whisk in the oil gradually and season with salt and freshly ground black pepper. Add the dressing to the chicory and mix well.
To serve, carve the chicken and place on to serving plates with the chicory salad and some of the juices from the chicken pan.
