Heat half of the olive oil in a large casserole dish over a moderate heat. Saute the onion and garlic until they just start to colour, then add the lamb mince and increase the heat. Brown well all over for 5 minutes, then add the wine, chopped tomatoes, cinnamon stick and ground oregano and cumin. Reduce to a simmer and cook gently for 30 minutes.
Meanwhile, heat the rest of the olive oil in batches in a frying pan set over a high heat until very hot. Fry the aubergine slices quickly until lightly golden on both sides. Once coloured, layer the slices in a shallow, heatproof 2 1/2 litre baking dish. Season between the aubergine layers with salt and pepper and set to one side.
Melt the butter for the topping in a saucepan over a medium heat, then whisk in the flour to create a roux. Cook for 1-2 minutes, whisking occasionally, then whisk in the milk in a slow, steady stream to create a thickened sauce. Simmer over a low heat for 8-10 minutes, stirring occasionally, then beat in the Parmesan and seasoning to taste. Remove from the heat and allow to cool for a few minutes before beating in the eggs.
Discard the cinnamon stick from the lamb sauce, then spoon it over the aubergine layer. Pour the topping over the lamb sauce and bake for 20-25 minutes until the top is golden brown and bubbling. Remove from the oven and allow it to sit for 5 minutes. Re-heat the rice if necessary then spoon the moussaka onto serving plates and garnish with the rice and a mixture of the lamb's lettuce and rocket. Garnish the moussaka with sprig.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.