Heat the oil in a large pan over a medium heat. Add the onion and cook for 4-5 mins, stirring occasionally, until brown.
Add the garlic and mix well. Add the aubergines, tomatoes, pesto, oregano, paprika, cumin, chilli powder and a good pinch of salt and pepper. Mix well.
Add 200ml of just-boiled water and mix. Bring to the boil, cover, reduce the heat to low, and cook for 1 hr, or until the aubergine cubes are soft and tender, and the sauce is thick.
Meanwhile, preheat the oven to gas 7, 220°C, fan 200°C. Add half the basil to the aubergines and mix well.
Arrange the halloumi slices over the top of the aubergines and cook for 15-20 mins, until the cheese is golden. Top with the remaining basil and serve immediately.
