Waffle Fry Cottage Pie

Name: Waffle Fry Cottage Pie
Ingredients: 1 tablespoon vegetable oil; 1 onion, finely diced; 2 carrots, finely diced; 1 celery stalk, finely diced; 2 garlic cloves, minced; 17 3/4 ounces lean beef mince; 2 tablespoons tomato purée; 2 tablespoons plain flour; 14 ounces chopped tomatoes; 8 1/2 fluid ounces beef stock; 2 tablespoons Worcestershire sauce; 1 bay leaf; 2 teaspoons thyme leaves, chopped; 1 pinch black pepper; 8 waffle fries; 1 3/4 ounces cheddar, finely grated; 7 ounces seasonal greens