Preheat the oven to 200°C/Fan 180°C/Gas 6. Give the potatoes a wash and then simmer them in salted water for 7 minutes and drain.
Meanwhile, fry the fish gently in a little olive oil, skin down, then place in a medium-sized baking dish. Fry the aubergine slices in the same pan, adding more oil if needed, allowing the fish flavours to soak into them.
Layer the fried aubergine slices on top of the fish. Slice the potatoes and layer on top of the aubergines.
Whisk all the ingredients for the sauce together and pour generously over the fish mixture. Scatter the breadcrumbs over the top and place in the oven
Bake for 15–20 minutes or until the breadcrumbs have gone golden and crispy.
Sprinkle with fresh parsley and serve with a wedge of lemon and your choice of green veg or salad.