Get a griddle pan hot. Cut the eggplants lengthwise into 1/2-inch/1cm slices, score them on one side, then place them on the griddle and let them cook, watching their progress carefully, until they are soft and nicely browned.
Pour the olive oil into a mixing bowl and season it with a little salt and black pepper. As each piece of eggplant comes from the grill, push it down into the olive oil, then set aside.
Put the yogurt in a medium bowl and add the chopped mint. Roughly chop the parsley, leaving the smaller, younger leaves whole, then stir all into the yogurt with a little ground black pepper. Crumble the feta cheese into small pieces and fold into the yogurt.
Spoon the feta dressing onto a serving dish. Lay the eggplant slices, without their oil, on top. Slice the pickled onions or chiles, then add them to the dish. Scatter the whole mint leaves, then spoon a little of the eggplant olive oil marinade over the top.