Wash the aubergines and cut them into slices 1 cm thick; put them in a colander, in layers, and sprinkle a little coarse salt on each layer. Place a plate on top and leave for about half an hour to extract the bitter water they contain. Then rinse the slices, one by one, and pat them dry with a cloth or kitchen paper (bear in mind, in the rest of the recipe, that the aubergine will remain slightly salty). Place the slices on a baking tray and season with salt, chilli pepper and oil. Set the oven to grill and cook them on both sides, until they’re golden brown. Boil the potato in a small saucepan with salted water. Chop the parsley and mint leaves. Set aside half of this chopped mixture, then put the other half in a bowl with the chopped onions, minced meat, egg and potato (which you will have mashed after removing it from the water it was boiled in). Mix everything together with your hands until you have a homogenous mixture. Dampen and squeeze out at sheet of greaseproof paper approx. 40 cm long; lay it out on your work surface. Place the minced meat mixture in the centre and shape it into a rectangle measuring roughly 30x26 cm. Cover the meat with the slices of aubergine, laying them one beside the other without overlapping. Roll the meatloaf up using the paper, which you will wrap round it, and tie the ends up with kitchen string. Heat the meatloaf, “wrapped up”, in a heavy-bottomed frying pan over a medium heat, without adding anything. When you see, through the paper, that the meat begins to brown, transfer it to an oven dish and cook it in a preheated oven, at 180 °C, for 30 minutes. When it’s cooked, open the paper, sprinkle the meatloaf with the chopped herbs you set aside, reclose the paper and leave to cool. Remove the paper and serve the meatloaf cut into fairly thick slices.