• 1 large knob of butter
• 1 onion, finely chopped
• 1 carrot, peeled and finely chopped
• 500g lean lamb mince
• 2 tbsp plain flour
• 500ml beef stock
• 1 dried bay leaf
• 1 tbsp Worcestershire sauce
• 1 tbsp tomato purée
• 1 handful of frozen peas, plus extra to decorate
• Salt and black pepper
• 800g potatoes, peeled and chopped into chunks
• 40g butter
• 125ml milk
• Melted butter, for brushing

1. Heat the butter in a large pot over a medium-high heat. When the butter is melted, add the onion, carrot and cook, stirring, for five minutes.
2. Add the minced lamb and break it up with a wooden spoon. Cook for five minutes or until the lamb turns brown. Add the flour and stir for two minutes.
3. Pour in the hot beef stock. Add the bay leaf, Worcestershire sauce, tomato purée and peas. Turn the heat up to high until everything begins to bubble and boil.
4. Reduce the heat to low and cook for another 30 minutes, stirring occasionally, until the sauce thickens. Taste the sauce and season with salt and pepper.
5. Put the chunks of potato into a large pot of salted boiling water. Cook for 15 minutes or until tender. Drain, then return the potatoes to the pan and add the butter.
6. Use a potato masher to mash until smooth, then stir in the milk. Season with salt and pepper.
7. Preheat oven to 200°C/180˚C fan/gas mark 6. Ladle the lamb mixture into a large ovenproof baking dish.
8. Spoon the potato into a freezer bag. Hold the bag at the open end, then use a scissors to cut one of the corners from the bottom. Use this bag to squeeze potato out onto the lamb mixture in the shape of Halloween ghosts – they can be as big or small as you’d like. Brush the ghosts with a little melted butter, then stick a few peas in as spooky green eyes!
9. Put the pie in the oven and bake for 20 minutes or until the ghosts are golden brown.