Wash the pork thoroughly, then sprinkle with salt and ground black pepper.

Preheat a large skillet over medium-high heat. Melt the butter.

Arrange the pork in the pan. Fry each side for 5-10 minutes, depending on the thickness of the chops. 

Take the pork out from heat and set it aside.

In the same pan, toss in the onions and saute for a minute. Add the mushrooms then stir. Cover and cook for 2 minutes.

Remove the cover and spread out the spinach without stirring. Cover again and cook for a minute.

Uncover; return the pork into the pan and slightly stir all together. Cover again and simmer for 5 minutes.

Done. Serve hot or warm.