Hearty Irish Shepherd's Pie with Colcannon Topping

Heat olive oil in a large oven-safe skillet or Dutch oven over medium-high heat. Add ground lamb and cook, breaking it up with a spoon, until browned, about 8-10 minutes. Drain any excess fat.

Add chopped onion, minced garlic, and diced carrots to the skillet. Cook over medium heat until vegetables soften, about 5-7 minutes.

Stir in frozen peas, beef broth, Worcestershire sauce, and dried thyme. Bring to a simmer, then reduce heat to low and cook for 10 minutes, allowing the flavors to meld and the sauce to thicken slightly.

While the filling simmers, boil the peeled and quartered potatoes in a large pot of salted water until very tender, about 15-20 minutes. Drain well.

In the same pot, wilt the shredded green cabbage over medium heat with 1 tablespoon of butter for 3-5 minutes until tender-crisp. Remove cabbage and set aside.

Return the drained potatoes to the pot. Add milk, remaining 3 tablespoons of butter, salt, and black pepper. Mash until smooth, then fold in the wilted cabbage to create the colcannon topping.

Pour the lamb filling into a 9x13 inch baking dish or leave it in the oven-safe skillet. Spread the colcannon topping evenly over the lamb mixture.

Bake at 375°F (190°C) for 25-30 minutes, or until the topping is golden brown and the filling is bubbling around the edges.

Let the pie rest for 5-10 minutes before serving to allow the filling to set.