Preheat the oven to 220ºC/200ºC fan-forced. Finely chop the brown onion and celery. Grate the carrot. Finely chop the garlic. Pick and finely chop the herb leaves.

In a large frying pan, heat a drizzle of olive oil over a high heat. Cook the onion, celery, and carrot, stirring, until softened, 4-6 minutes. Add the beef mince and cook, breaking it up with a spoon, until just browned, 3-4 minutes. Add the garlic and rosemary and cook, stirring, until fragrant, 1 minute. Reduce the heat to medium, then add the tomato paste, the water and beef-style stock powder and cook, stirring until reduced, 1-2 minutes. Season to taste. TIP: Add a dash more water if the mince is dry!

Transfer the beef to a baking dish and sprinkle over the grated Parmesan cheese.

In a small heatproof bowl, add the butter and microwave in 10 second bursts until melted. Brush each sheet of the filo pastry with the butter. Lightly scrunch each sheet of pastry and place on top of the beef mixture to completely cover. Bake the pie until the pastry is golden, 15-20 minutes.

While the pie is baking, cut the tomato into wedges. In a medium bowl, combine the salad leaves, tomato, a drizzle of balsamic vinegar and olive oil. Season.

Divide the cheesy beef and filo pastry pie between plates. Serve with the tomato and balsamic salad.