• Preheat oven to 200C (390C) with broiler on

Mashed Potato Topping

• Put potatoes in a pot, cover with cold water and sprinkle with salt
• Bring to a boil, reduce heat to medium and cook for 20-25 minutes or until a fork passes easily through the pieces
• Drain water from the pot. Add mustard, milk, salt and pepper into the pot with the potatoes and then mash

Meat Filling

• In the meantime, mix mince, salt, pepper and corn flour in a bowl
• In a large frying pan, heat oil over medium-high heat and cook onion and garlic for 1-2 minutes or until onions are soft
• Add mince and heat until cooked through; breaking up the meat with a heat-proof turner
• Add crushed tomatoes and carrots into the frying pan and cook for 5 minutes
• Add stock and Worcestershire sauce, bring to a boil, reduce heat to medium-low and simmer for 10 minutes
• Bring heat back up to medium, add peas (still frozen) into the frying pan and cook for 5 minutes
• Pour meat filling into a large, rectangular roasting dish
• Cover with the mashed potato, score vertically and horizontally across the top with a fork and sprinkle with grated cheese
• Put the pie in the 2nd from the top shelf of the oven and cook for approximately 15-20 minutes until top is browned