Preheat heat the oven to gas 4, 180°C, fan 160°C. Using a spoon, scoop the soft flesh from the rounded lower half of each aubergine and set aside. Put the shells on a baking sheet, brush with 1tbsp oil and season well. Bake for 15 minutes.
Meanwhile, heat the remaining oil in a large frying pan and finely chop the reserved aubergine flesh. Add the flesh to the pan along with the garlic, onion, celery and some seasoning. Cook for 10 minutes, until softened.
Tip the mixture into a bowl and stir in the bread cubes, olives, cheese, lemon zest and parsley, until combined.
Remove the shells from the oven and divide the mixture between each. Return to the oven for a further 25 minutes and bake unitl golden. Serve with salad, if you like.