1. Remove chicken from the fridge 20 to 30 minutes before cooking so it can get to room temperature, and season both sides with salt and pepper.
2. When the chicken is ready to cook, heat the olive oil in a large skillet over medium-high heat.
3. Once the skillet and olive oil are hot, lay the chicken in a single layer to cook for 3 to 4 minutes per side.
4. Once all the chicken is cooked, remove it from the skillet, set it aside on a plate, cover it with aluminum foil, and return the skillet to heat.
5. Once the skillet is empty and hot again, dump in the mushrooms to cook for 5 to 8 minutes.
6. After that time, add the garlic to the mushrooms and cook for another 1 to 2 minutes, until fragrant.
7. Once the vegetables are cooked, sprinkle the flour over them and stir it in, breaking up, for approximately 1 minute.
8. Once the flour is worked in, add the chicken broth and the italian seasoning to the skillet, stirring everything together and bringing it to a boil.
9. Once boiling, reduce the heat to simmer, add the chicken back in, along with the spinach, cover the skillet, and cook for 5 to 8 minutes.
10. After that time, the sauce should be nice and thick, but if it's too thick, add in a little water.
11. Once the sauce is the consistency you like, remove the skillet from the heat, stir in the yogurt, and serve the creamy chicken thighs with spinach and mushrooms immediately.
