Flavorful Potato and Onion Frittata (Oven-Baked)

Instructions:

1. Preheat your oven to 180 degrees Celsius (350 degrees Fahrenheit).
2. Lightly grease an oven-safe dish with cooking spray or oil. You can also line the dish with parchment paper for easier removal.
3. In a pan over medium heat, cook the onions with cooking spray for about 10 minutes, until softened and slightly browned.
4. While the onions cook, slice the cooked potatoes.
5. In a large bowl, whisk together the eggs and season with salt and pepper.
6. Combine the cooked onions, sliced potatoes, and egg mixture in the oven-safe dish. Mix well to ensure everything is evenly distributed.
7. Season the top of the mixture with a sprinkle of salt and pepper.
8. Bake the dish in the preheated oven for 25 minutes, or until the center is set and the top is golden brown.
9. Once cooked, remove the dish from the oven and let it cool slightly before serving.
10. Garnish with chopped fresh parsley for an extra pop of flavor (optional).

Tips:

1. For added protein, you can crumble cooked sausage or chorizo into the egg mixture before baking.
2. If you don’t have an oven-safe dish, you can cook the frittata on the stovetop following steps similar to a traditional Spanish tortilla.
3. Leftovers can be stored in the refrigerator for up to 3 days and reheated in the microwave or oven.