Reckon on 1 courgette and 1 aubergine between 3 people. Most importantly you need a wide-bottomed, heavy frying pan which doesn’t heat up too fast. And good olive oil.
Cover the bottom of the pan with olive oil. Aubergine soaks up plenty but then releases it again: they key is not to let everything dry out in the early stages nor to be swimming in oil by the end.
Slice the aubergine and courgette into very thin rings. Heat the oil and place the rings in it. The rings should bubble slightly at the edges as they go in, but not sizzle madly. Add salt, just a sprinkling over the top. If the aubergine and courgette is going in in multiple layers, add a small sprinkling between each layer. When the bottom layer starts to sizzle, take a large fish slice and turn everything over. Turn down the heat so the vegetables don’t burn. Keep turning every so often until they are all brown on both sides and soft, starting to fall apart.
Meanwhile, take a generous dollop of natural yoghurt. I like full-fat best. It has better taste and better consistency. Add to it a teaspoon of lemon juice and a handful of chopped fresh mint. Stir.
Taste the aubergine and courgettes, add more salt to taste if you think it needs it. Transfer to a serving dish. The yoghurt mix can either be spooned on top or put on the table to be added to portions individually.
NB: The key with this very simple dish is to get a big enough frying pan so that the courgette and aubergine cook through and brown evenly. If you are making it for more people, it can be done in a large dish in the oven.