Dry off the pork chops with paper towels. Heat up a 12 inch aluminium skillet over a medium flame. Pour 2 Tbl of peanut oil into the pan and brown the chops on one side. Turn over and season the browned sides with salt and pepper. Brown the other side, turn over and season them. Check the chops for doneness. Remove the chops from the pan and degrease the pan.
In the skillet, sweat the onions down with 2 Tbl of butter. Deglaze the pan with white wine. Scrape the bottom of the pan. Reduce the wine by about 1/2. Throw in the Sauce Espagnole. Adjust seasonings to taste. Reduce the sauce until it coats the back of a spoon. Stir in the mustard and cut off the heat. Ladle the sauce over, underneath or on along-side the chops.