Heat oven to 180°C
Drizzle aubergine halves in olive oil, sprinkle with salt and roast on a tray for 30 – 40 minutes (until they have collapsed a little and the inside flesh is very soft).
Meanwhile, bring a small saucepan of vegetable stock to the boil, add red split lentils, return to boil then cover and simmer for 5 minutes. Drain lentils but do not wash as this will remove the flavour of the stock.
Remove aubergines from the oven and carefully scoop out the inside flesh. Mash it with a fork until the texture is smooth. Return the aubergine casings to the roasting tray.
In a bowl combine aubergine flesh, lentils, cumin, ginger, chilli, lemon rind and juice, mint and harissa. Taste and season with salt and pepper as needed. As a final step gently fold through the crumbled feta.
Carefully divide and spoon the stuffing back inside each aubergine shell (without pressing down too much) and return to the oven for 10 – 15 minutes.
Serve hot with a drizzle of olive oil, extra crumbled feta and a garnish of fresh celery, coriander, or parsley leaves.