Turn the oven to 180°C, air circulation, and put your rack halfway in the oven.
Cut the aubergines in half lengthwise and scoop the pulp leaving just a bit so that the skin doesn’t fall apart. Roughly chop the pulp, sprinkle some salt over it and keep aside.
Place a large sauté pan over medium heat. Pour 2 tablespoons of oil. Sauté in batches the aubergines for 3-4 minutes, flesh side down only, until they get a bit golden brown. Remove from the pan and keep aside.
In the same pan over medium heat, add 3 tablespoons of oil and add the onions, sautéing for about 5 minutes until they become translucent. Add the minced meat and the garlic, increase the heat and continue sauteing until all the meat has been sautéed and a nice color has been achieved.
Add the tomatoes, the aubergines pulp along with the parsley, all-spice, coriander and oregano. Reduce the heat to low and simmer for about 10 minutes for all the ingredients to come together and the tomato juices to be absorbed. Season with salt and pepper to taste, add the feta and gently mix well and keep aside.
It’s Béchamel time!!
In a small saucepan boil the milk on low heat. Keep aside.
Place a medium size non-stick saucepan over low heat and add the butter, whisk, and once it melts and foams start adding the flour and keep on whisking to be just enough thick, a nice roux.
At this point start adding the warm milk, a bit at a time and keep on whisking. Add the nutmeg, salt and pepper and continue adding the milk and keep on whisking aiming to achieve a nice thick cream.
Remove from the fire and allow to cool for 5 minutes. While whisking the sauce add the egg yolks in a slow and steady stream. Béchamel is ready.
To put everything together...
Use a large baking dish and place the sautéed halved aubergines, skin side down, and add a bit of the minced meat mixture on their cut side pressing it down up to the level of the aubergines.
Finally use a spoon and add some of the Béchamel sauce. On top add couple of slices of the cherry tomatoes. Cook for 50 minutes aiming for the aubergines to soften and for the Béchamel sauce to get golden brown. Take out of the oven and allow for 15’ to cool. Sprinkle on top some parsley and serve.