Step 1

Preheat oven to 180°C/350°F.

Step 2

Heat oil in a large saucepan over high heat; cook beef and onion, stirring, for 5 minutes or until browned.

Step 3

Add carrot, celery, thyme, stock, sauce, paste and tomatoes; simmer, uncovered, for 30 minutes or until carrots are tender. Add peas; cook for 10 minutes or until peas are tender and the liquid has thickened.

Step 4

Meanwhile, to make mashed potato topping, boil, steam or microwave potatoes until tender; drain. Mash potato with butter and milk.

Step 5

Spoon beef mixture into a 2.5-litre (10-cup) ovenproof dish. Spread topping over beef mixture; sprinkle with cheese. Bake, uncovered, for 30 minutes or until pie is heated through and topping is golden. Serve sprinkled with extra thyme, if you like.