Slice the aubergines then fry them on both sides in a large pan with a little olive oil. Drain on kitchen paper. To save on washing up, use the same pan with a little more olive oil and fry off the onions and garlic.
After five minutes turn the heat up and add the lamb to brown it, then add the tomatoes. Add a good pinch of cumin and cinnamon with the wine and sauté together to break up the tomatoes. Add the chopped mint and the stock in stages.
In an ovenproof dish, layer the aubergines and lamb mince in a few layers, finishing with a layer of aubergines.
Combine the white sauce with the eggs, nutmeg and seasoning. Spoon over the top of the mince and then scatter with the grated cheese.
Bake in the oven 20-25minutes to colour the cheese and cook through.