Spinach Mushroom Breakfast Frittata

Let's Cook

1. Step 1.

   Preheat the oven to 325°F (165°C).

2. Step 2.

   Heat 1 tablespoon of olive oil in a 9-inch oven-safe skillet over medium-low heat. Once the oil is hot (a small drop of water should sizzle), add the chopped onion and sauté for 3 minutes, until it just starts to soften.

3. Step 3.

   Add the mushrooms to the skillet and sauté until they have shrunk, turned a bit darker, and are slightly tender, about 5 to 8 minutes.

4. Step 4.

   While the vegetables sauté, whisk together the eggs, thyme, and salt in a large bowl. Set aside.

5. Step 5.

   Add the garlic and baby spinach to the skillet and cook for another 5 minutes, or until the spinach is wilted.

6. Step 6.

   Remove the vegetables from the skillet and set aside.

7. Step 7.

   Return the skillet to the heat and add the remaining 1 tablespoon of olive oil, turning the pan to ensure the oil covers the bottom and sides.

8. Step 8.

   Pour the whisked eggs into the skillet and allow to cook undisturbed for about 1 minute before spreading the vegetable mixture as evenly as possible over the top. If using cheese, sprinkle it on top.

9. Step 9.

   Leave the skillet over the heat for another 2 to 3 minutes, just long enough for the edges of the frittata to start to set. Do not leave it too long, or the bottom will get too browned.

10. Step 10.

    Transfer the skillet to the middle rack of the oven and continue cooking for another 12 to 15 minutes. The frittata is finished when it has puffed up and the center doesn't jiggle when moved.

11. Step 11.

    Allow the frittata to rest for 3 minutes before serving. Store leftovers in an airtight container in the refrigerator for 3 to 4 days.