Slice the aubergine in half and slice it hasselback-style - slice the aubergine across the top, stopping about ¼ inch before reaching the bottom of the aubergine. The aubergine should stay in one piece.
Cover with oil and season the aubergine and bake to for 20 minutes.
Spread the tomato sauce in the bottom of a baking dish large enough to comfortably hold the aubergine halves.
Place slices of mozzarella and tomato in the cuts you’ve made in the aubergine, alternating between the 2. Sprinkle with parmesan and bake for a further 20 minutes or until the aubergine is cooked through.
Remove from the oven and sprinkle with the fresh basil leaves.