Sear the lamb in a large pan with no added oil until brown. Place in a colander and drain off any fat. Return to pan and add the onion and garlic and cook for 6 minutes.
While the lamb is cooking, brush the eggplant with oil and grill for about 3 - 4 minutes each side. Add the herbs, spices, tomato paste and vegetable stock to the lamb mixture and simmer until most of the liquid has absorbed.
Add the zucchini and chickpeas and remove from the heat and season with salt and black pepper.
Spoon a layer of the lamb mixture into an oven proof dish, followed by a layer of eggplant. Make another two layers with the remaining lamb and eggplant.
Set aside while you make the topping.
Combine the oats, parmesan, thyme and oil in a food processor and process until well combined. Season and spoon the mixture over the top.
Place in the oven and cook for 30 - 35 minutes until the top is brown and crunchy.