Preheat oven to 350°F (175°C). Grease a pie dish or quiche pan.
In a skillet, sauté diced onion until translucent, then add spinach and cook until wilted.
In a bowl, whisk together cottage cheese, eggs, garlic powder, black pepper, salt, and nutmeg. Stir in sautéed spinach and onion, then fold in mozzarella cheese.
Pour the mixture into the prepared dish and bake for 25-30 minutes, or until the quiche is set and the top is slightly golden.
