Shepherd's Pie with Root Vegetables

Prepare the Filling

1. 1Heat the olive oil in a large, ovenproof saucepan or casserole dish over medium heat. Add the chopped onion and cook for 5-7 minutes until softened.
2. 2Add the minced lamb to the pan and cook, breaking it up with a spoon, until browned all over. Drain off any excess fat.
3. 3Stir in the diced carrots, parsnips, celery, and minced garlic. Cook for another 5 minutes until the vegetables begin to soften.
4. 4Sprinkle the flour over the meat and vegetables, stirring well to coat. Cook for 1 minute.
5. 5Gradually pour in the stock, stirring constantly to avoid lumps. Add the tomato purée, Worcestershire sauce, and thyme. Bring the mixture to a simmer.
6. 6Season with salt and pepper to taste. Reduce the heat, cover the pan, and let it simmer gently for 20-25 minutes, or until the sauce has thickened and the vegetables are tender. Stir occasionally.

Prepare the Topping

1. 1Meanwhile, place the peeled and quartered potatoes in a large saucepan. Cover with cold water, add a pinch of salt, and bring to the boil. Cook for 15-20 minutes, or until tender when pierced with a fork.
2. 2Drain the potatoes thoroughly and return them to the hot pan for a minute to allow any excess moisture to evaporate.
3. 3Mash the potatoes until smooth. Add the butter and warm milk, mixing until creamy. Season with salt and pepper.

Assemble and Bake

1. 1Preheat your oven to 200°C (180°C fan/Gas Mark 6).
2. 2Spoon the mashed potato topping evenly over the lamb filling in the ovenproof dish. Use a fork to create peaks and textures on the surface, which will help it brown nicely.
3. 3If using, sprinkle the grated cheddar cheese over the mashed potato. Place the dish on a baking tray (to catch any drips) and bake for 20-25 minutes, or until the topping is golden brown and the filling is bubbling.
4. 4Allow to stand for 5-10 minutes before serving.