2 Cook spinach in 1/4 cup of water in a covered saucepan until just wilted, a couple minutes. Drain water and set aside.
3 In a mixing bowl, whisk together eggs, milk, and Parmesan cheese. Add in chopped sun-dried tomatoes, and sprinkle with salt and pepper. Set aside.
4 Sauté onions in olive oil in an oven-proof, stick-free skillet, until translucent, about 4-5 minutes on medium heat. Add garlic and cook a minute further. Add cooked spinach and mix in with onions and garlic.
5 Spread out spinach mixture evenly on bottom of skillet. Pour egg mixture over spinach mixture. Use a spatula to lift up the spinach mixture along the sides of the pan to let egg mixture flow underneath.
6 Sprinkle bits of goat cheese over the top of the frittata mixture. When the mixture is about half set, put the whole pan in the oven. Bake for 13-15 minutes, until frittata is puffy and golden. Remove from oven with oven mitts and let cool for several minutes.