- 3 tsp olive oil
- 600g/1lb 5oz lamb leg steaks, all visible fat removed (500g/1lb 2oz after the fat is cut off), cut into bite-size pieces
- 2 onions, roughly chopped
- 2 garlic cloves, thickly sliced
- 250g/9oz celery (about 4 stalks), thickly sliced
- 400g/14oz carrots (about 4 medium carrots), peeled and thickly sliced
- small handful fresh rosemary, finely chopped
- few sprigs fresh thyme
- 1 tbsp plain flour
- 1 beef stock pot diluted to make 500ml/18fl oz stock
- 2 tbsp Worcestershire sauce
- 2 tbsp tomato purée
- 650g/1lb 7oz floury potatoes, ideally Maris Piper, cut into thick slices
- salt and freshly ground black pepper
- Preheat the oven to 160C/140C Fan/Gas 3.
- Heat 1 teaspoon of the oil in a large heavy-bottomed casserole over a medium to high heat. Brown the lamb on all sides in two batches for 3-4 minutes per batch. Transfer to a plate using a slotted spoon.
- Add another teaspoon of oil to the pan and add the onions, garlic, celery and carrots and fry, stirring, for 3-4 minutes. Add the rosemary and thyme and fry for another minute. Sprinkle over the flour and cook for 2 minutes, stirring all the time to cook the flour.
- Return the lamb to the pan, pour in the stock and stir in the Worcestershire sauce and tomato purée, then bring to the boil.
- Layer the potatoes on top in two overlapping layers, seasoning between the layers. Cover with the lid and bake in the oven for 1½ hours, or until the lamb and the potatoes are tender.
- Remove the lid and increase the oven temperature to 200C/180C Fan/Gas 6. Brush the potatoes with the final teaspoon of oil and bake for a further 15 minutes, or until the top is nicely browned.