Heat oil in a frying pan over medium heat. Add lamb pieces and cook until brown on all sides. This step adds deep flavor. Remove the lamb and set aside for later use.

In the same pan, add onions and carrots. Cook for five minutes until soft. Stir often to avoid burning. The vegetables will become sweet and fragrant during this step.

Sprinkle flour over the vegetables and mix well. Slowly pour in the lamb stock while stirring. This creates a thick sauce. Add Worcestershire sauce, salt, and pepper for extra taste.

Return the browned lamb to the pan. Mix everything together gently. Let it simmer for ten minutes. This helps the flavors blend nicely and creates a rich base.

Transfer the lamb mixture into your casserole dish. Spread it evenly across the bottom. This ensures every bite has a balanced flavor and texture.

Arrange sliced potatoes on top of the lamb. Overlap them slightly for a neat look. Brush with melted butter to help them turn golden while baking.

Preheat your oven to 180°C. Place the dish inside and bake for about 90 minutes. The potatoes should be golden and crispy on top.

Remove the dish from the oven and let it rest for ten minutes. This helps the juices settle. Serve warm and enjoy your homemade comfort meal.