Classic Golden-Topped Shepherd's Pie

1.Prepare the Potatoes: Place the peeled and quartered potatoes in a large pot and cover with cold, salted water. Bring to a boil and cook for 15-20 minutes, or until fork-tender. Drain well.

2.Mash the Potatoes: Return the drained potatoes to the pot. Add the butter and warm milk/cream. Mash until smooth and creamy. Season with salt and pepper. Set aside.

3.Brown the Lamb: Heat the olive oil in a large, deep skillet or Dutch oven over medium-high heat. Add the ground lamb and cook, breaking it up with a spoon, until browned. Drain off any excess fat and set the lamb aside.

4.Sauté the Vegetables: Reduce the heat to medium. Add the chopped onion, carrots, and celery to the skillet. Cook for 8-10 minutes until the vegetables have softened. Add the minced garlic and cook for 1 minute until fragrant.

5.Build the Sauce: Stir in the tomato paste, dried thyme, and dried rosemary. Cook for 1 minute. Sprinkle the flour over the vegetables and stir well, cooking for 2 minutes to cook out the raw flour taste.

6.Simmer the Filling: Gradually pour in the beef stock, stirring constantly to prevent lumps. Add the Worcestershire sauce. Bring the mixture to a simmer, then reduce the heat to low and cook for 10-15 minutes, allowing the sauce to thicken. Stir in the reserved ground lamb and the frozen peas. Season the filling generously with salt and pepper.

7.Assemble the Pie: Preheat the oven to 200°C (400°F). Pour the lamb filling into a deep 9x13 inch (or similar sized) baking dish.

8.Top the Pie: Carefully spoon the mashed potato mixture over the lamb filling. Spread the potatoes evenly using a fork or spatula, ensuring the filling is completely covered. Create ridges or peaks with the fork for a crispier top. If desired, sprinkle the grated cheddar cheese over the potatoes.

9.Bake: Bake for 25-30 minutes, or until the potato topping is golden brown and the filling is bubbling hot around the edges. Let the pie rest for 10 minutes before serving.