Beef, Leek and Swede Cumberland Pie

Ingredients

• 2 Leeks, white part diced, green part sliced and kept separate
• 1 large Carrot, finely chopped
• 50g Butter
• 1 kg Beef Mince
• 1 tbsp Olive Oil, or vegetable oil
• 3 tbsp Plain Flour
• 5 Thyme Sprigs
• 2 tbsp Worcestershire Sauce
• 1 tbsp Marmite
• 1.2 L Beef Stock
• 100ml Milk
• a little Freshly Grated Nutmeg
• 25g Breadcrumbs
• 2 Celery Sticks, finely chopped
• 200g Unsmoked Bacon Lardons
• 350g Floury Potatoes, chopped into chunks
• 1kg Swede, about 2 large, peeled and chopped into chunks
• 25g Mature Cheddar, grated