Classic Shepherd's Pie with Fluffy Mashed Potato Crust | Can I Cook It?

Ingredients

• 500g minced lamb
• 1 large onion, finely diced
• 3 garlic cloves, minced
• 2 medium carrots, peeled and diced
• 2 tbsp tomato paste
• 200ml lamb or beef stock (1 stock cube dissolved in 200ml boiling water)
• 1 tbsp Worcestershire sauce
• 1 tsp dried thyme
• 1 tsp dried mixed herbs
• 2 bay leaves
• Salt and black pepper to taste
• 1 tbsp vegetable oil
• 800g floury potatoes, peeled and cut into chunks
• 50g butter
• 100ml milk