Heat oil in a large pan. Once hot, add onion, garlic and spices, and cook until onions are translucent. Add beef and bacon and cook until brown, making sure that any large clumps have been broken down. Add peas, gravy powder and chicken stock and let simmer for about 7 minutes until a thick sauce has been made. Let cool.
While waiting for the filling to cool, roll out the puff pastry and cut into rounds a little bit bigger than the tart shells (the pastry will shrink as it cooks).
Preheat an oven to 400F. Place the tart shells on a non-stick cookie sheet and fill with the meat mixture Place your pre-cut puff pastry round on top and brush it with a little egg wash. Place in the oven and cook for about 20 minutes, until the top has puffed up and turned golden brown. Take out of the oven and let sit for 5 minutes before serving. (This will ensure the gravy isn't too hot.)
Serve with your favourite salad and a glass of Mallee Rock Shiraz Cabernet Sauvignon.