1. Preheat oven to 350 degrees F.

2. In a large skillet, heat olive oil over medium heat. Add onion and garlic, and sauté until onion is soft, about 5 minutes.

3. Add spinach to skillet and cook until wilted, about 3 minutes. Remove from heat and let cool.

4. Place pie crust in a 9-inch pie plate. Add spinach mixture, spreading evenly. Sprinkle with salt.

5. In a medium bowl, whisk together eggs and half-and-half. Pour egg mixture over spinach. Sprinkle feta cheese over the top.

6. Bake in preheated oven for 35-40 minutes, or until top is golden brown and a knife inserted in center comes out clean. Let cool for 10 minutes before serving.