Preheat your oven to 400°F and slice the eggplant into 1/2-inch thick rounds.
Arrange the eggplant slices on a parchment-lined baking sheet, sprinkle with a pinch of sea salt, and roast for 15 minutes until tender.
While the eggplant roasts, heat the olive oil in a skillet over medium heat and sauté the diced yellow onion and minced garlic until translucent.
Add the ground lamb to the skillet, breaking it apart with a wooden spoon, and cook until fully browned; drain any excess fat from the pan.
Stir in the tomato puree, dried oregano, ground cinnamon, sea salt, and black pepper, then simmer for 5 minutes until the sauce has thickened.
In a small mixing bowl, whisk together the non-fat Greek yogurt and the large egg until the mixture is completely smooth.
In a small oven-safe baking dish, layer half of the roasted eggplant slices, followed by the lamb mixture, and then the remaining eggplant.
Pour the yogurt and egg mixture over the top layer, sprinkle with parmesan cheese, and bake for 20-25 minutes until the topping is golden brown and set.