Start by roasting the aubergines. Preheat the oven to 180°C or 350°F. Cut the aubergines in half lengthwise and score the inside by creating a crosshatch pattern. Be careful not to pierce the skin. Salt and oil the flesh. Bake for 40 minutes.
While the aubergines are baking, prepare the sauce. In a large pan, heat the olive oil and cook the onion for about 5 minutes. Once cooked add the garlic and let cook for another 5 minutes.
As soon as the onions and garlic are cooked, add the curry powder, cayenne powder, cinnamon, and tomato concentrate. Cook for about 3 minutes.
Break the minced meat, add it to the pan and let it cook. Season with salt and pepper.
Add the tomato passata and mix everything together. Let it simmer on low heat.
Once the aubergines are ready, take them out from the oven and let them cool slightly. Scoop the flesh of the aubergines, chop it up roughly and add to the sauce.
Stuff the emptied aubergines with sauce. Sprinkle with the grated parmesan cheese. Bake the stuffed aubergines until they are nicely brown in a 200°C or 430°F oven.
Take them out from the oven and let them rest slightly before serving.