Baked potato with mince

Name: Baked potato with mince
Ingredients: 2tbsp olive oil; 1 onion, finely chopped; 1 garlic clove, crushed; 1 carrot, finely chopped; 1 celery stick; 450g minced lamb; 2tbsp sun-dried tomato purée; 1tbsp Worcestershire sauce; 300ml beef stock; 2tsp cornflour; 4 baked potatoes; 80g cheddar, grated (optional)