Shepherd's Pie with Bubble and Squeak Topping

Prepare the Filling

1. Heat vegetable oil in a large oven-safe skillet or pot over medium-high heat.
2. Add the ground lamb and cook, breaking it up with a spoon, until browned. Drain off excess fat.
3. Add the chopped onion and diced carrots to the skillet. Cook until softened, about 5-7 minutes.
4. Stir in the minced garlic and cook for 1 minute more until fragrant.
5. Add the tomato paste and Worcestershire sauce, stirring to coat the meat and vegetables.
6. Pour in the beef broth and bring to a simmer. Reduce heat, cover, and let it cook for 15-20 minutes, or until the sauce has thickened.
7. Stir in the frozen peas. Season the filling with salt and black pepper to taste.

Make the Bubble and Squeak Topping

1. In a separate bowl, combine the cold mashed potatoes, shredded cooked cabbage, and chopped mixed cooked vegetables (if using).
2. Add the beaten egg to the potato and vegetable mixture and mix well. Season with salt and pepper.
3. Divide the potato mixture and spread it evenly over the meat filling in the skillet. You can create peaks and patterns with a fork for a rustic look.

Bake the Dish

1. Preheat your oven to 200°C (400°F).
2. Place the skillet (if oven-safe) or transfer the mixture to a baking dish.
3. Bake for 20-25 minutes, or until the topping is golden brown and crispy, and the filling is bubbling.
4. Melt the butter and brush or drizzle it over the bubble and squeak topping during the last 5-10 minutes of baking for extra crispiness.