In a large skillet over medium-high heat, add the oil. Season both sides of the chicken thighs with salt and pepper. Add the chicken thighs to the skillet skin side down, and cover with a splatter guard, if desired.
When the chicken skin is crispy and releases from the pan, flip them to the other side. Let cook until an internal temperature thermometer reads 165F. Remove from pan onto a plate and set aside. Pour out any grease that is left in the pan.
In the same skillet over medium heat, add the cream cheese, mayonnaise, sour cream, and stir to combine. Add the spinach and stir until thawed. Finally, add the Rotel and parmesan and stir until the parmesan is melted. Season with salt and pepper to taste.
You can add the chicken back to the skillet with the creamed spinach, or you can go ahead and serve the chicken on plates with a big spoonful of the creamy spinach.