1. Preheat your oven to 375°F (190°C) and grease a 9-inch pie dish with olive oil.
2. In a skillet, heat olive oil over medium heat and sauté onions and garlic until soft. Add sausage, breaking it apart until browned. Stir in spinach until wilted, then spread the mixture in the pie dish.
3. Whisk eggs, cream, and half of the cheese together. Season with salt and pepper. Pour over the sausage-spinach mixture. Top with remaining cheese.
4. Bake for 35-40 minutes or until the center is set. Let cool slightly before serving.

Notes:

• Feel free to swap sausage with a vegetarian alternative for a meat-free version.
• Adding a pinch of nutmeg or red pepper flakes can enhance the flavors.