Preheat the oven to 200 degrees. Cut the chicken into breasts and thighs, brush them with oil and salt, and place them in a roasting tin. Roast the breasts for about 30 minutes and the thighs for about 50 minutes in the hot oven. Leave the chicken to cool, remove the skin (setting it aside), and shred the meat finely. Reduce the oven temperature to 150 degrees. Peel the celeriac and cut it into 1/2 x 1/2 cm cubes. Toss the cubes with oil, salt and vinegar. Place them in a dish and bake in the oven for approx. 20 minutes until tender, then leave to cool.
Mix all the ingredients for the dressing thoroughly, then fold in the chicken and the roasted celeriac. Season to taste with sea salt, freshly ground pepper and, if desired, a little extra lemon juice. Chill the chicken salad and leave it to marinate for at least a couple of hours, or preferably overnight. Give it a stir before serving.
Cut the chicken skin into strips and then into tiny cubes, and fry them in a saucepan in the oil until crisp and golden, with the lid placed askew so the steam can escape. Stir the fat bits from time to time, but be careful as it will splatter quite a bit.
Separate the lamb’s lettuce into leaves, rinse them and soak them in ice-cold water for 10 minutes. Then place them in a salad spinner and spin them dry. Finely dice the apples and celery into 1/2 x 1/2 cm cubes. Finely chop the chives and toss the apples, celery and chives together. Place the chicken salad on rye bread, top with the romaine lettuce leaves and the apple mixture, and finish by sprinkling the crispy chicken skin over the top, along with the herbs and flowers.
