In a large frying pan heat the butter over moderately low heat.
Season pork with salt and pepper.
Raise heat to medium and add the chops to the pan and sauté for 7 minutes.
Turn and cook until chops are browned and done to medium, about 7-8 minutes longer or until the pork reads 160F in the center.
Remove the chops and put in a warm spot.
Add shallots to the pan and cook, stirring, until soft, about 3 minutes.
Add the stock to deglaze the pan, stir in the mustard, 1 tbsp parsley, then add mushrooms, season with fresh pepper and cook about 3 minutes, or until mushrooms are done.
Put the chops on a platter and pour the mushroom sauce over the meat, top with remaining parsley.