How to Make
Preheat the oven to 200˚C and place the rack close to the broiler/grill. Peel the aubergines and slice lengthways, approximately 1 cm thick. Brush both sides with 4 tbs of the vegetable oil and lay on a baking tray in one layer. Roast until golden brown on both sides. Remove and set aside to cool.
In a large pot heat 4 tbs of oil and brown the meat all over. Take a handful of the sliced onions and sautée for one minute. Add the celery, leeks, cinnamon stick, bay leaves, cardamom, and allspice berries. Pour the cold water to cover the meat and allow to come to a boil, skimming off the scum on the surface. Lower the heat to medium and cover to cook the meat until it is tender, for about 40 minutes. Strain the stock in a colander, with another pot under to catch the stock. Reserve the meat aside. Discard all of the vegetables.
While the meat is cooking, in a large skillet heat a ¼ cup vegetable oil and fry the remaining onions until golden and sweet. Remove and drain on paper towels. In another skillet, heat the butter and sautée the carrots until lightly golden, for about 2 minutes. Remove, sprinkle with 1 tsp cinnamon and set aside.
In a large 8-quart pot, place the aubergines vertically along the sides of the pot next to each other overlapping slightly, and go all the way around. Gently place the cooked lamb in the bottom as the first layer. Add the carrots, then scatter the fried onions over. Mix the cinnamon, allspice and turmeric into the drained rice and spoon over the carrot layer. Lastly, ladle the reserved stock to cover the rice completely. You might need to top it up with more water to cover the rice by 5 cm.
You may need to add a little hot water. Bring to the boil. Reduce the heat to a simmer, cover and leave until the rice is cooked and the liquid is absorbed. It will take about 20 minutes. Remove from the heat and leave the maqlouba covered for at least 30 minutes to rest before serving. Take a large platter bigger than the pot and invert turning everything upside down. Very slowly lift off the pot taking care not to topple the layers. Garnish with all of the toasted nuts. Serve immediately