Prepare vegetables. Slice the onion thinly, chop the carrot and sweet potato into small cubes and chop the broccoli and cauliflower into small florets.
Heat a large panto a medium heat then pour in the oil.
When the oil is hot, add in the onions and cook for 1-2 minutes until browned.
Break up the mince and add to the pan. Cook for 4-5 minutes until the mince has cooked and browned.
Don't drain any liquid out of the pan after cooking the mince because it will help cook the vegetables.
Add the chopped vegetables to the mince and cook for 5 minutes until they are soft.
Stir the canned tomatoes, Worcestershire sauce and gravy powder through the mince mixture and let it cook for about 5 minutes to allow the sauce to thicken.
Divide the mince into 4 small oven proof dishes. Alternatively, you can use one large pie dish.
Take the frozen sheet of puff pastry out of the freezer and leave to thaw for about 2 minutes so it can be cut easily. However, don't leave it out too long before using it because it will be difficult to lift up and will stick to your fingers.
Cut the pastry sheet into 4 squares and layer them over each dish. Prick small holes in the pastry with a fork. If using one large pie dish don't cut the pastry and just lay it on top.
Using a pastry brush, gently coat the pastry with a little bit of milk. You can just your fingers if you don't have a pastry brush.
The milk will cause the pastry to be golden brown on top.
Place into the oven and bake for 15-20 minutes until the pastry is brown and crispy on top. Serve with roasted potatoes and vegetables.