Start by washing and slicing the mushrooms, chopping the onion, and mincing the garlic. Cut the chicken into bite-sized pieces for even cooking.
In a large skillet, heat the olive oil over medium-high heat. Once hot, add the chopped onion and sauté for about 2-3 minutes until it becomes translucent.
Add the bite-sized chicken pieces to the skillet. Season with salt, pepper, thyme, and parsley. Cook for about 5-7 minutes, stirring occasionally, until the chicken is browned and cooked through.
Stir in the minced garlic and sliced mushrooms. Cook for an additional 4-5 minutes until the mushrooms are tender and have released their juices.
Pour in the chicken broth, scraping the bottom of the skillet to deglaze any browned bits. Bring to a simmer and let it cook for about 3 minutes.
Reduce the heat to low and stir in the heavy cream. Allow the sauce to thicken slightly, about 2-3 minutes. Add the fresh spinach and stir until wilted.
Taste and adjust the seasoning if needed. Serve this Chicken and Mushroom Skillet hot, perhaps over rice or pasta, or enjoy it on its own for a low-carb option!