Beef shepherd's pie

Name: Beef shepherd's pie
Prep time: 25 min
Cook time: 45 min
Total time: 1 h 10 min
Cuisine: European, British
Ingredients: 1 tablespoon olive oil; 1 brown onion, chopped; 1 large carrot, cut into 1cm pieces; 1 celery stick, cut into 1cm pieces; 2 garlic cloves, crushed; 1kg Coles Australian 3 Star Beef Mince; 2 tablespoons tomato paste; 400g can crushed tomatoes; 1 tablespoon Worcestershire sauce; 3/4 cup (185ml) beef stock; 1 cup (120g) frozen peas; 2 x 600g ctns Coles Fresh Mashed Potato; 1/2 cup (60g) grated cheddar; Mixed salad leaves, to serve