Shepherds pies

Name: Shepherd's pies
Ingredients: 1 tablespoon olive oil; 1 brown onion, finely chopped; 1 carrot, finely chopped; 2 celery sticks, finely chopped; 2 garlic cloves, crushed; 500g Coles Australian Lamb Mince; 2 tablespoons plain flour; 1 cup (250ml) beef stock; 2 tablespoons Worcestershire sauce; 1 tablespoon tomato paste; 1/2 cup (60g) frozen peas; 3 brushed potatoes, peeled, coarsely chopped; 1 swede, peeled, coarsely chopped; 40g butter, melted; 1/4 cup (60ml) milk; 1/2 cup (60g) coarsely grated cheddar; 20g butter, melted, extra