Preheat the oven to 200oC (fan 180C).

Place a large pan with one tbsp olive oil on the hob. Once the oil has heated up add the onion, carrot and leek to the pan and fry gently until they start to get a bit of colour.

Add the lamb and keep cooking for a couple more minutes then stir in the flour to absorb the juices.

Add the Worcestershire sauce to the pan to deglaze and then add the stock. Simmer for 10 minutes, stirring occasionally, then season.

Tip the lamb mix into an ovenproof dish. Slice the potatoes and layer them on top. Brush the top with the remaining olive oil and season.

Cook in the oven for around 30 minutes until the potatoes are golden.