Preheat the oven to 425°F.
Whisk together the egg, yogurt, salt and pepper; set mixture aside.
Heat olive oil in a large (10-inch) oven safe pan or cast iron pan. Add green onions and cook until softened, about 3-5 minutes. Add the spinach and garlic, and cook until the spinach starts to wilt, about 2-3 more minutes.
Pour the egg mixture on top of the cooked vegetables. Add half the feta cheese and half the sundried tomatoes.
Bake uncovered in the preheated oven until the center is set, and not jiggly, about 10-12 minutes. Add the remaining feta cheese and sundried tomatoes on top, and sprinkle with parsley. Serve immediately.
