GoodtoKnow

Name: GoodtoKnow
Prep time: 50 min
Cook time: 1 h 30 min
Total time: 2 h 20 min
Cuisine: British
Ingredients: 1.5kg (3lb) free-range chicken; 1 carrot, peeled, cut into chunks; 2 celery sticks, cut into chunks; 2 onions, peeled and chopped; 2 bay leaf; 1 tbs olive oil; 2 leeks, trimmed and sliced thickly; 150g (5oz) bacon lardons, smoked or unsmoked; 60g (2oz) butter; 60g (2oz) plain flour; 3 tbs crème fraîche, optional; 1 tbs coarse-grain mustard; A few thyme sprigs; Salt and ground black pepper; 375g pack ready-made puff pastry; A little beaten egg; 1.5-2 litre (2½-3½ pints) pie dish