Preheat the oven to 190°C.
Fry sliced aubergines in 4 tablespoons of olive oil for 2-3 minutes and drain on kitchen paper.
Sauté chopped onion and garlic in remaining oil until softened.
Add lamb mince and cook for 5 minutes until browned.
Stir in tomatoes, cumin, cinnamon, oregano, and red wine while breaking up tomatoes.
Add 2 tablespoons of mint and lamb stock, then simmer for 15 minutes.
Layer the meat sauce and fried aubergines in a baking dish.
Melt butter, stir in flour for 1 minute, and whisk in hot milk until thickened.
Stir in eggs, nutmeg, and half the cheeses until smooth.
Pour cheese sauce over the lamb and sprinkle with remaining cheese.
Bake for 20-25 minutes until golden and bubbling.
Griddle oiled courgette ribbons until charred and mix with lemon juice and more mint.
Serve moussaka slices with the prepared courgettes.