Circassian Chicken

Name: Circassian Chicken
Prep time: 30 min
Cook time: 2 h
Total time: 2 h
Yield: 8 portions
Ingredients: 1000 g water; 1 onion; 1 celery stalk; 2 sprigs fresh thyme; 2 bay leaves; 1 lemon; 8 black peppercorns; 8 cloves; 1 pinch chilli flakes; 1 uncooked, whole chicken; 60 g walnut oil; 4 tsp sweet paprika; 2 slices sourdough bread; 40 g unsalted butter; 50 g red onion; 3 garlic cloves; ½ tsp hot paprika; 175 g halved walnuts; fine sea salt; ground black pepper; 150 g natural yoghurt; 10 g fresh tarragon leaves