01 - Preheat oven to 375°F. Grease an 8x8 inch baking dish with olive oil or non-stick spray.
02 - Rinse quinoa thoroughly. Combine quinoa and water in a saucepan, bring to boil, then reduce heat, cover, and simmer 12-15 minutes until water is absorbed. Set aside to cool.
03 - Heat olive oil in a skillet over medium heat. Cook onion 2-3 minutes until softened. Add garlic and cook 1 minute. Add spinach and cook 2-3 minutes until wilted.
04 - Whisk eggs, milk, salt, pepper, and nutmeg in a bowl. Stir in cooked quinoa, spinach mixture, parsley, and half the cheese until combined.
05 - Pour mixture into prepared dish. Sprinkle remaining cheese on top. Bake 25-30 minutes until center is set and top is golden brown.
06 - Let cool 5 minutes before slicing. Garnish with extra parsley if desired. Serve warm.