Preheat your oven to 400°F (200°C).
In a skillet over medium heat, add the olive oil and sauté the diced yellow onion and minced garlic until soft and fragrant.
Add the ground lamb to the skillet, breaking it up with a spoon, and season with ground cumin, ground coriander, sea salt, and black pepper.
Once the lamb is browned, stir in the cubed eggplant and cook for 5 minutes until the eggplant begins to soften.
Transfer the lamb and eggplant mixture into a small oven-safe baking dish, spreading it into an even layer.
In a small bowl, whisk together the non-fat Greek yogurt and the egg until smooth, then pour the mixture evenly over the lamb.
Place the dish in the oven and bake for 15 to 20 minutes, or until the yogurt topping is set and has turned a light golden brown.
Remove from the oven and garnish with freshly chopped parsley before serving.