Method
To make the pie filing, put half–fat butter and rapeseed oil into a pan and heat until both are sizzling. Add the chopped onion, celery, mushrooms and carrots and fry for 7–10 minutes, or until golden.
Add cornflour and cook until light brown, and then gradually mix in the beef stock. Stir until sauce comes to the boil and thickens.
Mix in tomato purée and add parsley, and then cover the pan and simmer for approximately 30 minutes. Next, season to taste.
Cook the mince, then add a little cold water and allow it to cool. Drain off the fat and water.
Add the mince to the vegetables and transfer to a 2 pint pie dish.
To make the cheesy leek potato topping, boil potatoes and then mash with butter and milk. Beat over a low heat until creamy.
Next, fry the leeks gently in the remaining butter until it is soft. Add the cooked leeks to the mashed potatoes and mix.
Place the mixture evenly over the Shepherd’s pie dish. Sprinkle with grated cheese and place the pie into a pre–heated oven at 170ºC for 15–20 minutes.