Preheat your oven to 350°F (175°C). Grease a 9-inch pie dish or quiche pan with cooking spray or a little olive oil.

In a large skillet over medium heat, add the olive oil and sauté the chopped onion until translucent and soft, about 3-4 minutes. Add the minced garlic and cook for an additional 1 minute until fragrant. Remove from heat.

In a mixing bowl, combine the cottage cheese, eggs, milk, salt, pepper, and nutmeg. Whisk until well blended and creamy.

Stir in the sautéed onion and garlic mixture, followed by the chopped spinach, shredded mozzarella, and grated Parmesan cheese. Mix everything until evenly combined.

Pour the mixture into the prepared pie dish, spreading it evenly.

Bake in the preheated oven for 35-40 minutes, or until the quiche is set in the center and lightly golden on the edges.

Remove from the oven and let it cool for about 5-10 minutes before slicing. Serve warm or at room temperature.