Preheat oven to 400 degrees F. Chop spinach and set aside. In a mixing bowl, whisk eggs, milk, and parmesan cheese. Add sun-dried tomatoes, salt, and pepper, and set aside. Sauté chopped onions in olive oil in an OVENPROOF skillet until translucent. Add the garlic and chopped spinach. Cook for another minute. Spread the spinach mixture out evenly along the bottom of the pan. Pour egg mixture into the pan and use a spatula to gently lift the sides to allow egg to run underneath. Sprinkle goat cheese on top of the mixture.