Preheat the oven to 180°C (350°F).

Prepare the filling:

• In a heavy-based saucepan over medium heat, add oil, onion, thyme, and marjoram. Sauté for about 5 minutes until onions become translucent.
• Add lamb and Worcestershire sauce, braising for 5 to 10 minutes until the meat is browned on all sides
• Stir in tomatoes, rosemary, beef stock, vegetables, salt, and pepper. Mix well, breaking up the tomatoes with a spoon.
• Reduce heat to low-medium, cover, and simmer for 15 minutes.
• Lower the heat further, sprinkle flour over the mixture, and blend thoroughly. Cover and cook for about an hour, stirring frequently to prevent burning. Adjust seasoning to taste.

Prepare the potato topping:

• Place potatoes in a saucepan and cover with cold water.
• Bring to a boil over high heat, then reduce heat to low-medium and cover. Cook until potatoes are fork-tender.
• Drain the potatoes and mash with butter, salt, ½ cup of cheddar cheese, and milk until smooth.

Assemble and bake:

• Transfer the meat and vegetable mixture into a prepared oven dish.
• Spread the mashed potatoes evenly over the top, spoonful by spoonful.
• Sprinkle the remaining ½ cup of shredded cheese over the mashed potatoes.
• Bake uncovered for 15 minutes or until the cheese is melted and golden brown.

Serve:

• Let the shepherd’s pie sit for a few minutes before serving.
• Serve hot with a fresh salad on the side.

TIPS AND VARIATIONS:

• Make It Ahead: Assemble the pie a day in advance. Cover and refrigerate. When ready to serve, bake directly from the fridge, adding 10 minutes to the baking time.
• For Extra Flavour: Add a splash of red wine or balsamic vinegar to the filling during cooking for added depth.
• Vegetarian Option: Substitute the lamb with lentils or a plant-based meat alternative. Use vegetable stock instead of beef stock.
• Spice It Up: For a bit of heat, add a pinch of chili flakes or smoked paprika to the filling.