Preheat oven to 400°F (200°C).

In a large skillet over medium heat, cook ground lamb (900 g) until browned, breaking it up with a spoon.

Lamb is browned and no longer pink

Drain off any excess fat.

Add onion, carrots (2 medium), and celery to the skillet. Cook until softened, about 5-7 minutes.

Vegetables are softened and translucent

Stir in garlic (2 cloves), beef broth (2 cups), frozen peas (1 cup), Worcestershire sauce (2 tsp), and dried thyme (1 tsp). Bring to a simmer.

Simmer for 15-20 minutes, or until the sauce has thickened slightly.

Sauce has thickened enough to coat the back of a spoon

Season with salt (1 tsp) and pepper to taste.

While the lamb mixture is simmering, boil potatoes in salted water until tender, about 15-20 minutes.

Potatoes are easily pierced with a fork

Drain potatoes and return them to the pot.

Mash potatoes with 1/4 cup butter (½ cups) and milk (½ cups) until smooth and creamy. Season with salt (1 tsp) and pepper to taste.

Potatoes are smooth with no lumps

Transfer the lamb mixture to a 9x13 inch baking dish.

Spread the mashed potatoes evenly over the lamb mixture.

Potatoes cover the lamb completely

Dot the top of the mashed potatoes with the remaining 1/4 cup butter (½ cups).

Bake for 20-25 minutes, or until the mashed potatoes are golden brown and slightly crispy.

Mashed potatoes are golden brown and slightly crispy • Aroma of browned butter and savory lamb

Let stand for 5-10 minutes before serving.