Let’s get cooking! Follow these simple steps to bring this dish to life:

1. Heat the olive oil in a large skillet over medium heat. Add the sliced sweet onions and cook until they become soft and translucent, stirring occasionally, about 5-7 minutes.
2. Add the sliced mushrooms to the skillet and cook for another 5 minutes, or until they release their juices and start to brown. This is where the magic happens, and the kitchen starts to fill with that irresistible aroma.
3. Stir in the minced garlic and cook for about 1 minute, just until fragrant. Be careful not to let it burn!
4. Add the fresh spinach to the skillet, a handful at a time, allowing it to wilt down before adding more. This should take about 3-4 minutes.
5. Season the mixture with salt, pepper, and dried thyme, if using. Stir to combine all the flavors.
6. Once everything is well mixed and the spinach is fully wilted, remove from heat. If desired, sprinkle with grated Parmesan cheese before serving.

Pro tip: Using a non-stick skillet can make this process even smoother, especially if you’re like me and sometimes get distracted by a toddler or two!