Step 1: Season the chicken thighs generously with salt, pepper, and dried thyme on both sides.
Step 2: Heat olive oil and butter in a large skillet over medium-high heat. Add the chicken and sear for 5-7 minutes per side until golden brown and cooked through. Remove chicken and set aside.
Step 3: In the same skillet, add the sliced mushrooms. Cook for 5 minutes until browned and moisture has evaporated.
Step 4: Add the minced garlic and cook for 1 minute until fragrant. Pour in the chicken broth to deglaze the pan, scraping the bottom with a wooden spoon.
Step 5: Reduce heat to medium-low and pour in the heavy cream. Let it simmer for 2-3 minutes until slightly thickened.
Step 6: Stir in the parmesan cheese until melted and smooth. Add the fresh spinach and stir until wilted.
Step 7: Return the chicken to the skillet, spooning the sauce over the top. Simmer for another 2 minutes to heat through and serve.