BBC Food - Recipes - Nigel Slater's Lancashire hotpot

Ingredients

• 6 lamb chops , weighing approximately 500g/1lb 2oz in total
• 3 tbsp olive oil
• 1 large carrot , roughly chopped
• 1 celery stalk, trimmed, roughly chopped
• 1 large onion , roughly chopped
• 2 tbsp plain flour
• 1 litre/1¾ pints beef stock
• 8 sprigs fresh thyme
• 1 bay leaf
• 100g/3½oz butter , melted
• 2 large floury potatoes , such as Maris Piper, sliced into 1cm/½in-thick discs
• salt and freshly ground black pepper