Preheat the oven to 200ºC/fan 180ºC/gas mark 4. Put the aubergine slices on a baking tray and brush with half the olive oil. Bake for 15 minutes, until softened.
Meanwhile, cook the lentils in a pan of boiling water for 15 minutes, adding the carrots for the final 7 minutes of cooking time. Drain.
Heat the remaining oil in a large frying pan. Add the garlic and fry gently for 3-4 minutes, then add the cinnamon, tomatoes, tomato paste and the drained lentils and carrots to the pan. Simmer for 10 minutes. Remove from the heat and stir in most of the chopped parsley.
Preheat the grill to high. Layer the lentil mix and aubergine slices in a large baking dish, finishing with a layer of aubergine slices. Spoon over the cheese sauce, then place under the grill for 5 minutes, until the top is golden. Garnish with the remaining parsley to serve.